Display control method, storage medium, and computer device

Abstract

Disclosed in embodiments of the present application are a display control method, a storage medium, and a computer device. The method comprises: displaying a whiteboard interface; determining a current display area in a display state in a whiteboard page that has undergone a non-drawing operation; determining a content area containing all drawn contents in the whiteboard page; determining a target area; on the basis of a control display area of a preview control and the target area, determining a control display position of the target area in the preview control; and displaying the target area in the control display position.

Description

Display control method, storage medium and computer device

[0001] This application claims priority to Chinese patent application filed on February 4, 2024, with application number 202410169000.8 and application name “A display control method, device, storage medium and computer equipment”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of information processing technology, and in particular to a display control method, device, and computer-readable storage medium. Background Art

[0003] With the rapid development of technology, people's work and life are becoming increasingly inseparable from electronic devices. Among them, the use of electronic whiteboards is also increasing. Especially in commercial display equipment, whiteboard applications are basically indispensable and often become an important factor in measuring the value and competitiveness of commercial display equipment.

[0004] In the prior art, whiteboard applications generally support operations of zooming and panning the canvas to provide users with a larger drawing area. In particular, some whiteboard applications support an infinite canvas to allow users to infinitely pan the canvas. Technical issues

[0005] In order to enable users to quickly determine the relative position of the current display area of ​​the whiteboard in the entire whiteboard page during zooming or panning, a preview control is provided. However, in the case where the user continues to pan, for example, the identifier used to display the current display area in the preview control (for example, displaying the current display area in blue in the preview control) will move out of the control display area of ​​the preview control as the panning operation occurs, causing the user to be unable to determine the relative position of the current display area in the whiteboard page, thereby reducing the user experience. Technical Solutions

[0006] The embodiments of the present application provide a display control method, device, and computer-readable storage medium, which can avoid the problem that the user cannot determine the relative position of the current display area in the whiteboard page, thereby improving the user experience.

[0007] To solve the above technical problems, the embodiments of the present application provide the following technical solutions:

[0008] A display control method, comprising:

[0009] Display a whiteboard interface, wherein the whiteboard interface is used to display the display area currently in the display state in the whiteboard page;

[0010] In response to a non-drawing operation on the whiteboard interface, determining a current display area in a displayed state in the whiteboard page after the non-drawing operation;

[0011] Determine a content area containing all drawn content in the whiteboard page;

[0012] Determine a target area based on the current display area and the content area, where the target area is a minimum area including the target display area and the content area;

[0013] Determining a control display position of the target area in the preview control based on the control display area of ​​the preview control and the target area;

[0014] The target area is displayed at the control display position.

[0015] A display control device, comprising:

[0016] A first display module is used to display a whiteboard interface, wherein the whiteboard interface is used to display a display area currently in a display state in a whiteboard page;

[0017] A first determining module is configured to, in response to a non-drawing operation on the whiteboard interface, determine a current display area in a displayed state in the whiteboard page after the non-drawing operation;

[0018] A second determining module is used to determine a content area containing all drawn content in the whiteboard page;

[0019] a third determining module, configured to determine a target area based on the current display area and the content area, wherein the target area is a minimum area including the target display area and the content area;

[0020] A fourth determining module, configured to determine a control display position of the target area in the preview control based on the control display area of ​​the preview control and the target area;

[0021] The second display module is configured to display the target area at the control display position.

[0022] In some embodiments, the fourth determining module includes:

[0023] A first determining submodule, configured to determine a scaling ratio for displaying the target area in the control display area according to a first size of the target area in the whiteboard page and a second size of the control display area;

[0024] a second determining submodule, configured to determine a transformation matrix based on the first size, the second size, and the scaling ratio;

[0025] The third determining submodule is configured to determine a control display position of the target area in the preview control according to the transformation matrix.

[0026] In some embodiments, the first size includes a first width and a first height, the second size includes a second width and a second height, and the first determining submodule is configured to:

[0027] Calculating a ratio of the first width to the second width to obtain a width ratio;

[0028] Calculating a ratio of the first height to the second height to obtain a height ratio;

[0029] The width ratio and the height ratio are compared, and the larger ratio is determined as the scaling ratio.

[0030] In some embodiments, the second determining submodule is configured to:

[0031] Calculating a ratio of the first width to the scaling ratio to obtain a target width of the target area within the control display area;

[0032] Calculating a ratio of the first height to the scaling ratio to obtain a target height of the target area within the control display area;

[0033] Calculate half of the difference between the second width and the target width to obtain the target horizontal coordinate of the upper left corner of the target area within the control display area;

[0034] Calculate half of the difference between the second height and the target height to obtain the target vertical coordinate of the upper left corner of the target area within the control display area;

[0035] Determine the target horizontal coordinate and the target vertical coordinate as the first coordinate of the upper left corner of the target area in the preview control;

[0036] A transformation matrix is ​​determined based on the second coordinate of the upper left corner vertex of the target area in the whiteboard page, the first coordinate, and the scaling ratio.

[0037] In some embodiments, the apparatus further comprises:

[0038] A fifth determining module, configured to determine whether it is the first time that a non-drawing operation is received;

[0039] The drawing module is configured to draw the content area and store it in a designated storage area if it is determined that the non-drawing operation is received for the first time, and prohibit displaying the preview control.

[0040] In some embodiments, the apparatus further comprises:

[0041] The acquisition module is used to, if it is determined that this is not the first time that a non-drawing operation is received, obtain the drawn content area from the designated storage area during the process of displaying the target area at the control display position, and display the content area at the target position corresponding to the content area in the control display area.

[0042] In some embodiments, the current display area within the preview control is displayed in a specified style, and the device further includes:

[0043] a sixth determining module, configured to determine a current position of the current display area in the preview control in response to a non-drawing operation on the current display area displayed in a specified style in the preview control;

[0044] a seventh determining module, configured to determine an inverse transformation matrix according to the transformation matrix;

[0045] an eighth determining module, configured to determine a changed position of the current display area within the whiteboard page based on the current position and the inverse transformation matrix;

[0046] The adjustment module is used to adjust the current display area in the whiteboard page to the changed position.

[0047] A computer-readable storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor to execute the steps in the above-mentioned display control method.

[0048] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the display control method described above are implemented. A computer program product or computer program includes computer instructions stored in a storage medium. The computer instructions are read from the storage medium by the processor of the computer device and executed by the processor, causing the computer device to execute the steps of the display control method described above. Beneficial effects

[0049] The embodiment of the present application displays a whiteboard interface, wherein the whiteboard interface is used to display the display area currently in the display state in the whiteboard page; in response to a non-drawing operation on the whiteboard interface, determines the current display area in the display state in the whiteboard page after the non-drawing operation; determines the content area containing all the drawn content in the whiteboard page; based on the current display area and the content area, determines a target area, wherein the target area is the minimum area containing the target display area and the content area; based on the control display area of ​​the preview control and the target area, determines the control display position of the target area in the preview control; and displays the target area at the control display position. In this way, each time the user performs a non-drawing operation, the target area will be determined, and the target area including the current display area and the content area will be fully displayed in the preview control, avoiding the problem that the user cannot determine the relative position of the current display area in the whiteboard page, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0051] FIG1 is a schematic diagram of a scene of a display control system provided by an embodiment of the present application;

[0052] FIG2 is a flow chart of a display control method according to an embodiment of the present application;

[0053] FIG3 is a first schematic diagram of a whiteboard page provided in an embodiment of the present application;

[0054] FIG4 is a second schematic diagram of a whiteboard page provided in an embodiment of the present application;

[0055] FIG5 is a third schematic diagram of a whiteboard page provided in an embodiment of the present application;

[0056] FIG6 is a schematic diagram of determining the first coordinate of the upper left corner vertex of the target area within the control display area according to an embodiment of the present application;

[0057] FIG7 is a display diagram of a preview control provided in an embodiment of the present application;

[0058] FIG8 is a schematic diagram of the overall design of the preview control provided in an embodiment of the present application;

[0059] FIG9 is a signaling diagram for initializing a preview control according to an embodiment of the present application;

[0060] FIG10 is a schematic structural diagram of a display control device provided in an embodiment of the present application;

[0061] FIG11 is a schematic diagram of the structure of a terminal provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0062] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0063] Embodiments of the present application provide a display control method, device, and computer-readable storage medium.

[0064] Please refer to Figure 1, which is a schematic diagram of a scenario of a content display system provided in an embodiment of the present application, including: terminal A and server B. Terminal A and server B can be connected via a communication network. The communication network includes wireless networks and wired networks, where wireless networks include one or more combinations of wireless wide area networks, wireless local area networks, wireless metropolitan area network, and wireless personal network. The network includes network entities such as routers and gateways, which are not shown in the figure. Terminal A can exchange information with server B via the communication network. For example, server B can send display content to different terminals A for display.

[0065] The content display system may include a content display device, which may be integrated into a terminal such as a tablet computer, mobile phone, laptop computer, or desktop computer that has a storage unit and a microprocessor and has computing capabilities. In FIG1 , the terminal is terminal A in FIG1 , and various application software required by the user may be installed in terminal A, such as teaching application software and video presentation application software. Terminal A may be used to display a whiteboard interface, wherein the whiteboard interface is used to display a display area currently in a display state on a whiteboard page; in response to a non-drawing operation on the whiteboard interface, determine the current display area of ​​the whiteboard page that is in a display state after the non-drawing operation; determine a content area that includes all drawn content on the whiteboard page; determine a target area based on the current display area and the content area, wherein the target area is the minimum area that includes the target display area and the content area; determine a control display position of the target area in the preview control based on a control display area of ​​the preview control and the target area; and display the target area at the control display position.

[0066] The server B can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers. It can also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, as well as big data and artificial intelligence platforms, which are used to store and distribute display content.

[0067] It should be noted that the scenario diagram of the content display system shown in Figure 1 is merely an example. The content display system and scenario described in the embodiment of the present application are intended to more clearly illustrate the technical solution of the embodiment of the present application, and do not constitute a limitation on the technical solution provided in the embodiment of the present application. Ordinary technicians in this field can know that with the evolution of the content display system and the emergence of new business scenarios, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

[0068] It should be noted that some processes described in the specification, claims, and figures above include multiple steps that appear in a specific order. However, it should be understood that these steps may be executed in a different order than the order in which they appear herein or in parallel. The step numbers are used solely to distinguish between the different steps and do not themselves represent any order of execution. Furthermore, terms such as "first," "second," or "target" are used herein to distinguish similar objects and are not necessarily used to describe a specific order or precedence.

[0069] The following are detailed descriptions of each.

[0070] An embodiment of the present application provides a display control method, which can be executed by a terminal.

[0071] Please refer to Figure 2, which is a flow chart of a display control method provided by an embodiment of the present application. The display control method includes: in step 101, displaying a whiteboard interface, wherein the whiteboard interface is used to display the display area currently in display state in the whiteboard page.

[0072] With the rapid development of electronic technology, smart interactive tablets have been widely used in fields such as teaching and conferencing, greatly facilitating people's work and learning. In actual use, smart interactive tablets display content, which is the whiteboard interface. The whiteboard interface includes a display area where the whiteboard page is displayed and a toolbar located at the top of the whiteboard page. The display area can be teaching content or meeting content. Users can control different areas of the whiteboard page as the display area through operations such as sliding and zooming.

[0073] In step 102 , in response to a non-drawing operation on the whiteboard interface, a current display area in a displayed state in the whiteboard page after the non-drawing operation is determined.

[0074] Among them, the operations that users can perform on the whiteboard interface include two types of operations. The first type of operation is drawing operations, such as painting, writing, etc. on the whiteboard page; the second type of operation is non-drawing operations, such as controlling the whiteboard page to translate or zoom.

[0075] Specifically, since non-drawing operations are used to change the content displayed on the whiteboard interface, each time a user performs a non-drawing operation, the displayed area of ​​the whiteboard page is changed. Therefore, when responding to a non-drawing operation on the whiteboard interface, the current displayed area of ​​the whiteboard page after the non-drawing operation is completed is determined.

[0076] As shown in Figure 3, which is a first schematic diagram of a whiteboard page provided in an embodiment of the present application, taking display area A before a non-drawing operation is performed as an example, when a user slides their finger in the whiteboard interface, the entire whiteboard page shifts to the lower left, and the current display area is finally fixed at area B. Area B is then the current display area in the whiteboard page that is in display after the non-drawing operation.

[0077] In some implementations, after the step of responding to a non-drawing operation on the whiteboard interface, the method further includes:

[0078] (1) Determine whether it is the first time to receive a non-drawing operation;

[0079] (2) If it is determined that the non-drawing operation is received for the first time, the content area is drawn and stored in a designated storage area, and the preview control is prohibited from being displayed.

[0080] Among them, in order to improve the display rate of the content area in the control display area of ​​the preview control, the present application draws and stores the content area in a designated storage area, so that when the content area needs to be displayed in the control display area of ​​the preview control in the future, the pre-drawn content area can be extracted from the designated storage area and directly placed in the control display area, thereby achieving the effect of exchanging storage space for drawing time.

[0081] Specifically, after responding to the non-drawing operation on the whiteboard interface, it is necessary to determine whether this is the first time a non-drawing operation is received after the whiteboard interface is opened. If so, the preview control is not displayed during this non-drawing operation, and the content area is drawn and stored in the designated storage area.

[0082] The designated storage area can be a cached Bitmap, the size of which can be the same as the second size of the control display area in the preview control. When the content area can be completely drawn in the cached Bitmap without any scaling, all drawn content can be drawn to the cached Bitmap by aligning the upper left corner of the content area with the upper left corner of the cached Bitmap. When the content area cannot be completely drawn to the cached Bitmap without being scaled down, the scaling ratio of the content area can be calculated, and then all drawn content can be drawn to the cached Bitmap by aligning the upper left corner of the content area with the upper left corner of the cached Bitmap.

[0083] In step 103, a content area including all drawn contents in the whiteboard page is determined.

[0084] The content area is the smallest area on the whiteboard page that includes all the drawn contents drawn by the user.

[0085] Please refer to Figure 4, which is a second schematic diagram of a whiteboard page provided in an embodiment of the present application. The whiteboard page in Figure 4 includes three drawn elements: a circle, a wavy line, and a five-pointed star. The bottom area including the circle, the wavy line, and the five-pointed star, i.e., area C, is determined as the content area.

[0086] In step 104 , a target area is determined based on the current display area and the content area. The target area is the smallest area including the target display area and the content area.

[0087] Among them, after the current display area is determined in step 102 and the content area is determined in step 103, in order to completely display the current display area and the content area in the preview control, it is necessary to determine the minimum area that includes the target display area and the content area. This area is the target area.

[0088] Please refer to Figure 5, which is a third schematic diagram of a whiteboard page provided in an embodiment of the present application. Region B in Figure 5 is the current display area; region C is the content area; the smallest region containing regions B and C is region D, and region D is the target region.

[0089] In step 105 , based on the control display area of ​​the preview control and the target area, a control display position of the target area in the preview control is determined.

[0090] The preview control is used to display the control of the whiteboard page in a zoomed form. Since the target area needs to be zoomed and displayed within the control display area of ​​the preview control, the control display position of the target area in the preview control needs to be determined.

[0091] In some implementations, the step of determining a control display position of the target area in the preview control based on the control display area of ​​the preview control and the target area includes:

[0092] (1) determining a scaling ratio for displaying the target area within the control display area according to a first size of the target area in the whiteboard page and a second size of the control display area;

[0093] (1) determining a transformation matrix based on the first size, the second size, and the scaling ratio;

[0094] (1) Determine the control display position of the target area in the preview control according to the transformation matrix.

[0095] Among them, since the user's non-drawing operations include translation and / or scaling, and the two operations correspond to different transformation matrices, in order to determine the control display position of the target area in the preview control, it is first necessary to determine the transformation matrix.

[0096] Specifically, the transformation matrix is ​​determined as follows: determining the actual size of the target area in the whiteboard page, that is, the first size, and determining the actual size of the control display area used for display in the preview control, that is, the second size; determining the scaling ratio based on the first size and the second size; determining the transformation matrix based on the first size, the second size and the scaling ratio; and finally determining the control display position of the target area in the preview control based on the transformation matrix.

[0097] In some embodiments, the first size includes a first width and a first height, the second size includes a second width and a second height, and the step of determining a scaling ratio for displaying the target area in the control display area based on the first size of the target area in the whiteboard page and the second size of the control display area includes:

[0098] (1.1) calculating a ratio of the first width to the second width to obtain a width ratio;

[0099] (1.2) calculating a ratio of the first height to the second height to obtain a height ratio;

[0100] (1.3) Compare the width ratio and the height ratio, and determine the larger ratio as the scaling ratio.

[0101] Among them, since the target area and the control display area are rectangular in shape, the scaling ratio can be determined based on the width and height of the rectangle. First, the ratio of the width of the target area (i.e., the first width) to the width of the control display area (i.e., the second width) is calculated to obtain the width ratio; then the ratio of the height of the target area (i.e., the first height) to the height of the control display area (i.e., the second height) is calculated to obtain the height ratio; in order to fully display the target area in the control display area, it is necessary to select the larger ratio from the width ratio and the height ratio to determine the scaling ratio.

[0102] For example, if the first width is 10 cm, the first height is 4 cm, the second width is 5 cm, and the second height is 4 cm, then the width ratio is 10 / 5=2, and the height ratio is 4 / 4=1. The larger ratio is the width ratio, and the scaling ratio is 2. In this way, after scaling, the scaled width of the target area is 5 cm, and the scaled height is 2 cm, ensuring that the width of the target area can be completely displayed in the control display area.

[0103] In some embodiments, the step of determining a transformation matrix based on the first size, the second size, and the scaling ratio includes:

[0104] (1.1) calculating the ratio of the first width to the scaling ratio to obtain a target width of the target area within the control display area;

[0105] (1.1) calculating the ratio of the first height to the scaling ratio to obtain a target height of the target area within the control display area;

[0106] (1.3) calculating half of the difference between the second width and the target width to obtain the target horizontal coordinate of the upper left corner of the target area within the control display area;

[0107] (1.4) calculating half of the difference between the second height and the target height to obtain the target vertical coordinate of the upper left corner of the target area within the control display area;

[0108] (1.5) determining the target horizontal coordinate and the target vertical coordinate as the first coordinate of the upper left corner of the target area in the preview control;

[0109] (1.6) Determine a transformation matrix based on the second coordinate of the upper left corner vertex of the target area in the whiteboard page, the first coordinate, and the scaling ratio.

[0110] Among them, based on the first size, the second size and the scaling ratio, a specific method of determining the transformation matrix is: calculating the ratio of the first width to the scaling ratio to obtain the target width of the target area in the control display area; calculating the ratio of the first height to the scaling ratio to obtain the target height of the target area in the control display area; calculating half of the difference between the second width and the target width to obtain the target horizontal coordinate of the upper left corner vertex of the target area in the control display area; calculating half of the difference between the second height and the target height to obtain the target vertical coordinate of the upper left corner vertex of the target area in the control display area; determining the target horizontal coordinate and the target vertical coordinate as the first coordinate of the upper left corner vertex of the target area in the preview control; and determining the transformation matrix based on the second coordinate of the upper left corner vertex of the target area in the whiteboard page, the first coordinate and the scaling ratio.

[0111] Please refer to Figure 6, which is a schematic diagram of determining the first coordinates of the upper left corner vertex of the target area in the control display area provided by an embodiment of the present application. Among them, area E is the control display area with a width of W2 and a height of H2, and area D' is the display area of ​​the target area in the control display area, with a width of W1 and a height of H1. In order to determine the first coordinates of the upper left corner vertex of the target area in the control display area (that is, the coordinates of point a in Figure 6), it is necessary to calculate half of the difference between W2 and W1 to obtain the target horizontal coordinates of the upper left corner vertex of the target area in the control display area; calculate half of the difference between H2 and H1 to obtain the target vertical coordinates of the upper left corner vertex of the target area in the control display area, thereby obtaining the horizontal and vertical coordinates of point a. After determining the first coordinate of point a, the transformation matrix can be determined in combination with the second coordinates of the upper left corner vertex of the target area in the whiteboard page and the scaling ratio.

[0112] In some implementations, the transformation matrix is ​​determined based on the second coordinate of the upper left corner vertex of the target area on the whiteboard page, the first coordinate, and the scaling ratio as follows:

[0113] If the non-drawing operation is a translation operation, the difference between the target horizontal coordinate and the horizontal coordinate in the second coordinate is calculated to obtain a horizontal translation amount;

[0114] Calculate the difference between the target vertical coordinate and the vertical coordinate in the second coordinate to obtain the longitudinal translation;

[0115] A transformation matrix is ​​determined based on the horizontal translation amount and the vertical translation amount.

[0116] For example, if the first coordinate is (10, 5) and the second coordinate is (6, 4), then the horizontal translation is 10-6=4 and the vertical translation is 5-4=1, and the transformation matrix is ​​N(4, 1).

[0117] If the non-drawing operation is a scaling operation, the transformation matrix is ​​M(scaling ratio, abscissa of the second coordinate, ordinate of the second coordinate).

[0118] For example, if the scaling factor is 2, the horizontal coordinate of the second coordinate is 3, and the vertical coordinate is 4, then the transformation matrix is ​​M(2,3,4).

[0119] If the non-drawing operation includes both a translation operation and a scaling operation, the transformation matrix is ​​the product of the translation transformation matrix and the scaling transformation matrix.

[0120] For example, if the translation transformation matrix is ​​N(4,1) and the scaling transformation matrix is ​​M(2,3,4), the product is N(4,1)*M(2,3,4). In step 106, the target area is displayed at the control display position.

[0121] After the control display position is determined in step 105 , each point in the target area may be displayed within the control display position according to the control display position calculated after the transformation matrix.

[0122] Please refer to Figure 7, which is a schematic diagram of the preview control provided in an embodiment of the present application. The preview control 10 in Figure 7 includes a control display area 11, in which a zoom image D' corresponding to the target area D of the current display area B and the content area D of the whiteboard page is displayed.

[0123] In some embodiments, the method further comprises:

[0124] If it is determined that this is not the first time a non-drawing operation is received, then in the process of displaying the target area at the control display position, the drawn content area is obtained from the designated storage area, and the content area is displayed at the target position corresponding to the content area in the control display area.

[0125] Among them, if it is determined that the non-drawing operation received this time is not the first time after the whiteboard interface is opened, then in the process of displaying the target area at the control display position, since the target area also includes the content area, the pre-drawn content area can be obtained from the designated storage area, and the content area can be displayed at the target position corresponding to the content area in the control display area.

[0126] Specifically, the target position corresponding to the content area in the control display area can also be calculated by combining the coordinate information of the content area with the transformation matrix, which will not be described in detail here.

[0127] In some embodiments, the current display area in the preview control is displayed in a specified style, and after the step of displaying the target area at the control display position, the method further includes:

[0128] (1) determining a current position of the current display area in the preview control in response to a non-drawing operation on the current display area displayed in a specified style in the preview control;

[0129] (2) determining an inverse transformation matrix according to the transformation matrix;

[0130] (3) determining a change position of the current display area within the whiteboard page based on the current position and the inverse transformation matrix;

[0131] (4) Adjusting the current display area in the whiteboard page to the changed position.

[0132] The current display area within the preview control is displayed in a specified style, such as a highlighted display. The user can perform non-drawing operations such as translation and / or scaling on the current display area within the preview control, thereby reversely controlling the current display area on the whiteboard page through the preview control. After the non-drawing operation, the current position of the current display area within the preview control is determined; an inverse transformation matrix is ​​determined based on the transformation matrix; a changed position of the current display area within the whiteboard page is determined based on the current position and the inverse transformation matrix; and the current display area within the whiteboard page is adjusted to the changed position.

[0133] Specifically, the method of determining the inverse transformation matrix according to the transformation matrix is ​​as follows: performing the inverse operation on the numbers in the translation transformation matrix to obtain the translation inverse transformation matrix; performing the inverse operation on the scaling ratio in the scaling transformation matrix to obtain the scaling inverse transformation matrix. For example, if the transformation matrix is ​​N(3,4)*M(1.5,-1,-2), the corresponding inverse transformation matrix is ​​M(2 / 3,-1,-2)*N(-3,-4). As can be seen from the above, the embodiment of the present application displays a whiteboard interface, which is used to display the display area currently in the display state in the whiteboard page; in response to a non-drawing operation on the whiteboard interface, determines the current display area in the display state of the whiteboard page after the non-drawing operation; determines the content area containing all the drawn content in the whiteboard page; based on the current display area and the content area, determines the target area, which is the minimum area containing the target display area and the content area; based on the control display area of ​​the preview control and the target area, determines the control display position of the target area in the preview control; and displays the target area at the control display position. In this way, every time the user performs a non-drawing operation, the target area will be determined, and the target area including the current display area and the content area will be completely displayed in the preview control, avoiding the problem that the user cannot determine the relative position of the current display area in the whiteboard page, thereby improving the user experience.

[0134] Please refer to Figure 8, which is a schematic diagram of the overall design of the preview control provided in an embodiment of the present application. The preview control includes two functions: control initialization function and control display function.

[0135] The control initialization function is as follows: When opening the whiteboard page, the global view control's external interface method, init(), is first called to initialize the control. Its initialization tasks include: initializing the control's internal data and state; starting the drawing sub-thread, waiting for the control to update its drawing tasks; starting the cached Bitmap drawing sub-thread, waiting for the whiteboard elements to be completely drawn to the cached Bitmap; and monitoring the whiteboard page's declaration cycle state changes. When the whiteboard page is closed, it actively resets internal data / state, interrupts the drawing tasks, stops the drawing sub-thread, and stops the cached Bitmap drawing sub-thread.

[0136] The function of the display control is: when the user starts to zoom or pan the whiteboard canvas, the interface method show() provided by the control is called to display the control and get the ShowOperation instance. Its main functions are: when continuing to zoom / pan the canvas, the interface method update() provided by the ShowOperation instance is called to update the global view control display; when the hand is raised to stop zooming / panning the canvas, the interface method closeDelay() provided by the ShowOperation instance is called to automatically hide the global view after a delay of 3s; when the user performs other operations (such as writing, erasing, clicking buttons on the toolbar, switching pages, etc.), the global view needs to be hidden immediately as needed. At this time, the interface method closeImmediately() provided by the ShowOperation instance needs to be called. After the global view control is hidden, the control's show() method needs to be called again before the next zoom or pan of the canvas.

[0137] Please refer to Figure 9, which is a signaling diagram for preview control initialization provided by an embodiment of the present application. After the user opens the whiteboard application, the whiteboard enters the initialization phase and initializes the preview control (i.e., the global view control); the preview control is triggered to enter the data and state initialization phase; the preview control monitors the whiteboard page lifecycle changes and registers with the whiteboard to perform cleanup when the whiteboard page is closed; after registration is completed, the preview control starts the preview control drawing sub-thread and waits for drawing tasks; after the drawing sub-thread is started, the cached bitmap drawing sub-thread is started, waiting for the task of fully displaying the content area (i.e., the whiteboard elements) in the cached bitmap; after the cached bitmap is started, the preview control is initialized and the whiteboard initialization is completed. Among them, when the preview control is initialized, the user starts to perform non-drawing operations, and the whiteboard calls show() to start the display process; the preview control obtains the whiteboard page background information, zoom information, and element drawing snapshot list from the whiteboard page; the data in the preview control is updated (calculating the size and position of the content area), the state is updated, and the control drawing information is generated; the preview control drawing process is triggered; the preview control drawing sub-thread draws the background and foreground until the drawing is completed; the preview control triggers the cached Bitmap drawing, and the cached Bitmap drawing sub-thread traverses the whiteboard element drawing snapshot list and draws it to the specified position of the cached Bitmap; after the drawing is completed, the control state of the preview control is updated; the preview control triggers the control drawing sub-thread to refresh the control display, and the control drawing sub-thread draws the background, draws the cached Bitmap to the target area of ​​the preview control, and draws the foreground; informs the preview control that the drawing is completed, and the preview control updates the control state; the cached Bitmap drawing task is completed; generates an instance ShowOperation of the updated preview control, so that the instance is displayed in the preview control.

[0138] When the preview control is displayed, the control display is updated by calling the update interface update(); the delayed closing task of automatically hiding the preview control after the preset delay time (for example, 3s) is removed; the latest drawing information is generated; the preview control is triggered to update the drawing; the preview control drawing sub-thread draws the background, draws the cached Bitmap to the target area of ​​the preview control, and draws the foreground; the preview control is informed that the drawing is completed, and the preview control updates the control state.

[0139] When the user stops non-drawing operations, the delayed closing interface closeDelay() is called to trigger the preview control to automatically hide after the preset delay time; the ShowOperation interface triggers the delayed closing task; when the delayed preset time task is not canceled, the preview control is hidden, the control state is reset, and the trigger ends.

[0140] When the user performs non-drawing operations on the current display area in the preview control, the whiteboard application controls the preview control to handle the non-drawing operation events; the preview control removes the automatic hiding task and calculates the latest drawing data; the preview control is triggered to refresh the drawing content, and the preview control drawing sub-thread performs drawing until the drawing is completed.

[0141] To facilitate better implementation of the display control method provided in the embodiment of the present application, the embodiment of the present application also provides a device based on the above display control method. The meanings of the terms are the same as those in the above display control method, and the specific implementation details can be referred to the description in the method embodiment.

[0142] Please refer to Figure 10, which is a structural schematic diagram of the display control device provided in an embodiment of the present application, wherein the display control device is applied to a terminal and may include a first display module 301, a first determination module 302, a second determination module 303, a third determination module 304, a fourth determination module 305 and a second display module 306, etc.

[0143] The first display module 301 is used to display a whiteboard interface, wherein the whiteboard interface is used to display the display area currently in the display state in the whiteboard page;

[0144] A first determining module 302 is configured to, in response to a non-drawing operation on the whiteboard interface, determine a current display area in a displayed state in the whiteboard page after the non-drawing operation;

[0145] The second determining module 303 is used to determine a content area containing all drawn contents in the whiteboard page;

[0146] A third determining module 304 is configured to determine a target area based on the current display area and the content area, where the target area is a minimum area including the target display area and the content area;

[0147] A fourth determining module 305 is configured to determine a control display position of the target area in the preview control based on the control display area of ​​the preview control and the target area;

[0148] The second display module 306 is configured to display the target area at the control display position.

[0149] In some embodiments, the fourth determining module 305 includes:

[0150] A first determining submodule, configured to determine a scaling ratio for displaying the target area in the control display area according to a first size of the target area in the whiteboard page and a second size of the control display area;

[0151] The second determining submodule is configured to determine a transformation matrix based on the first size, the second size, and the scaling ratio; and the third determining submodule is configured to determine a control display position of the target area in the preview control according to the transformation matrix.

[0152] In some embodiments, the first size includes a first width and a first height, the second size includes a second width and a second height, and the first determining submodule is configured to:

[0153] Calculating a ratio of the first width to the second width to obtain a width ratio;

[0154] Calculating a ratio of the first height to the second height to obtain a height ratio;

[0155] The width ratio and the height ratio are compared, and the larger ratio is determined as the scaling ratio.

[0156] In some embodiments, the second determining submodule is configured to:

[0157] Calculating a ratio of the first width to the scaling ratio to obtain a target width of the target area within the control display area;

[0158] Calculating a ratio of the first height to the scaling ratio to obtain a target height of the target area within the control display area;

[0159] Calculate half of the difference between the second width and the target width to obtain the target horizontal coordinate of the upper left corner of the target area within the control display area;

[0160] Calculate half of the difference between the second height and the target height to obtain the target vertical coordinate of the upper left corner of the target area within the control display area;

[0161] Determine the target horizontal coordinate and the target vertical coordinate as the first coordinate of the upper left corner of the target area in the preview control;

[0162] A transformation matrix is ​​determined based on the second coordinate of the upper left corner vertex of the target area in the whiteboard page, the first coordinate, and the scaling ratio.

[0163] In some embodiments, the apparatus further comprises:

[0164] A fifth determining module, configured to determine whether it is the first time that a non-drawing operation is received;

[0165] The drawing module is configured to draw the content area and store it in a designated storage area if it is determined that the non-drawing operation is received for the first time, and prohibit displaying the preview control.

[0166] In some embodiments, the apparatus further comprises:

[0167] The acquisition module is used to, if it is determined that this is not the first time that a non-drawing operation is received, obtain the drawn content area from the designated storage area during the process of displaying the target area at the control display position, and display the content area at the target position corresponding to the content area in the control display area.

[0168] In some embodiments, the current display area within the preview control is displayed in a specified style, and the device further includes:

[0169] a sixth determining module, configured to determine a current position of the current display area in the preview control in response to a non-drawing operation on the current display area displayed in a specified style in the preview control;

[0170] a seventh determining module, configured to determine an inverse transformation matrix according to the transformation matrix;

[0171] an eighth determining module, configured to determine a changed position of the current display area within the whiteboard page based on the current position and the inverse transformation matrix;

[0172] The adjustment module is used to adjust the current display area in the whiteboard page to the changed position.

[0173] In the above embodiments, the description of each embodiment has its own focus. For the part that is not described in detail in a certain embodiment, please refer to the detailed description of the display control method above, and will not be repeated here.

[0174] The present application also provides a computer device, which may be a terminal. FIG11 shows a schematic diagram of the structure of the terminal involved in the present application. Specifically:

[0175] The computer device may include components such as a radio frequency (RF) circuit 401, a memory 402 including one or more computer-readable storage media, an input unit 403, a display unit 404, a sensor 405, an audio circuit 406, a wireless fidelity (WiFi) module 407, a processor 408 including one or more processing cores, and a power supply 409. It will be understood by those skilled in the art that the terminal structure shown in FIG11 does not limit the terminal and may include more or fewer components than shown, or combine certain components, or arrange the components differently. Among them:

[0176] The RF circuit 401 can be used to receive and send signals during information transmission or calls. In particular, after receiving downlink information from the base station, it is handed over to one or more processors 408 for processing; in addition, uplink data is sent to the base station. Generally, the RF circuit 401 includes but is not limited to an antenna, at least one amplifier, a tuner, one or more oscillators, a subscriber identity module (SIM) card, a transceiver, a coupler, a low noise amplifier (LNA), a duplexer, etc. In addition, the RF circuit 401 can also communicate with the network and other devices through wireless communication. Wireless communication can use any communication standard or protocol, including but not limited to Global System of Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Messaging Service (SMS), etc.

[0177] The memory 402 can be used to store software programs and modules. The processor 408 executes various functional applications and display control by running the software programs and modules stored in the memory 402. The memory 402 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, at least one application required for a function (such as a sound playback function, an image playback function, etc.); the data storage area may store data created according to the use of the terminal (such as audio data, a phone book, etc.). In addition, the memory 402 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage device. Accordingly, the memory 402 may also include a memory controller to provide the processor 408 and the input unit 403 with access to the memory 402.

[0178] The input unit 403 can be used to receive input digital or character information and generate keyboard, mouse, joystick, optical, or trackball signal input related to user settings and function control. Specifically, in one embodiment, the input unit 403 may include a touch-sensitive surface and other input devices. A touch-sensitive surface, also known as a touch display or touchpad, can detect user touch operations on or near it (for example, operations performed by a user using a finger, stylus, or any other suitable object or accessory on or near the touch-sensitive surface) and drive corresponding connected devices according to a pre-set program. Optionally, the touch-sensitive surface may include a touch detection device and a touch controller. The touch detection device detects the user's touch direction and detects signals generated by the touch operation, transmitting the signals to the touch controller. The touch controller receives the touch information from the touch detection device, converts it into touch point coordinates, and then sends it to the processor 408. It can also receive and execute commands from the processor 408. In addition, touch-sensitive surfaces can be implemented using various types, such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch-sensitive surface, the input unit 403 may also include other input devices. Specifically, other input devices may include, but are not limited to, one or more of a physical keyboard, function keys (such as a volume control key, a switch key, etc.), a trackball, a mouse, a joystick, and the like.

[0179] The display unit 404 can be used to display information input by the user or information provided to the user and various graphical user interfaces of the terminal, which can be composed of graphics, text, icons, videos and any combination thereof. The display unit 404 may include a display panel. Optionally, the display panel can be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), etc. Further, the touch-sensitive surface can cover the display panel. When the touch-sensitive surface detects a touch operation on or near it, it is transmitted to the processor 408 to determine the type of touch event. The processor 408 then provides a corresponding visual output on the display panel based on the type of touch event. Although in Figure 11, the touch-sensitive surface and the display panel are implemented as two independent components to implement input and output functions, in some embodiments, the touch-sensitive surface and the display panel can be integrated to implement input and output functions.

[0180] The terminal may also include at least one sensor 405, such as a light sensor, a motion sensor, and other sensors. Specifically, the light sensor may include an ambient light sensor and a proximity sensor, wherein the ambient light sensor may adjust the brightness of the display panel according to the brightness of the ambient light, and the proximity sensor may turn off the display panel and / or backlight when the terminal is moved to the ear. As a type of motion sensor, the gravity acceleration sensor can detect the magnitude of acceleration in all directions (generally three axes), and can detect the magnitude and direction of gravity when stationary. It can be used for applications that identify the posture of the mobile phone (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer, tapping), etc.; as for other sensors that can be configured in the terminal, such as gyroscopes, barometers, hygrometers, thermometers, infrared sensors, etc., they will not be described here.

[0181] Audio circuit 406, a speaker, and a microphone provide an audio interface between the user and the terminal. Audio circuit 406 converts received audio data into electrical signals and transmits them to the speaker, which then converts them into sound signals for output. Conversely, the microphone converts collected sound signals into electrical signals, which are then received by audio circuit 406 and converted into audio data. The audio data is then processed by processor 408 and transmitted via RF circuit 401 to, for example, another terminal. Alternatively, the audio data can be output to memory 402 for further processing. Audio circuit 406 may also include an earphone jack to allow communication between an external headset and the terminal.

[0182] WiFi is a short-range wireless transmission technology. The terminal can help users send and receive emails, browse web pages, and access streaming media through WiFi module 407, providing users with wireless broadband Internet access. Although FIG11 shows WiFi module 407, it is understood that it is not a required component of the terminal and can be omitted as needed without changing the essence of the invention.

[0183] Processor 408 is the terminal's control center, connecting all components of the phone using various interfaces and circuits. By running or executing software programs and / or modules stored in memory 402 and accessing data stored in memory 402, it executes various terminal functions and processes data, thereby providing overall monitoring of the phone. Optionally, processor 408 may include one or more processing cores; preferably, processor 408 may integrate an application processor and a modem processor, with the application processor primarily handling the operating system, user interface, and application programs, while the modem processor primarily handles wireless communications. It is understood that the modem processor may not be integrated into processor 408.

[0184] The terminal also includes a power supply 409 (e.g., a battery) for supplying power to various components. Preferably, the power supply can be logically connected to the processor 408 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The power supply 409 can also include one or more DC or AC power supplies, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator, and other arbitrary components.

[0185] Although not shown, the terminal may also include a camera, a Bluetooth module, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 408 in the terminal will load the executable files corresponding to the processes of one or more application programs into the memory 402 according to the following instructions, and the processor 408 will run the stored display whiteboard interface, which is used to display the display area currently in the display state of the whiteboard page;

[0186] In response to a non-drawing operation on the whiteboard interface, determining a current display area in a displayed state in the whiteboard page after the non-drawing operation;

[0187] Determine a content area containing all drawn content in the whiteboard page;

[0188] Determine a target area based on the current display area and the content area, where the target area is a minimum area including the target display area and the content area;

[0189] Determining a control display position of the target area in the preview control based on the control display area of ​​the preview control and the target area;

[0190] The target area is displayed at the control display position.

[0191] In the above embodiments, the description of each embodiment has its own focus. For the part that is not described in detail in a certain embodiment, please refer to the detailed description of the display control method above, and will not be repeated here.

[0192] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be accomplished by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0193] To this end, an embodiment of the present application provides a computer-readable storage medium storing a plurality of instructions that can be loaded by a processor to execute the steps of any of the display control methods provided in the embodiments of the present application. For example, the instructions can execute the following steps:

[0194] Display a whiteboard interface, wherein the whiteboard interface is used to display the display area currently in the display state in the whiteboard page;

[0195] In response to a non-drawing operation on the whiteboard interface, determining a current display area in a displayed state in the whiteboard page after the non-drawing operation;

[0196] Determine a content area containing all drawn content in the whiteboard page;

[0197] Determine a target area based on the current display area and the content area, where the target area is a minimum area including the target display area and the content area;

[0198] Determining a control display position of the target area in the preview control based on the control display area of ​​the preview control and the target area;

[0199] The target area is displayed at the control display position.

[0200] According to one aspect of the present application, a computer program product or computer program is provided, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the methods provided in the various optional implementations provided in the above embodiments.

[0201] The specific implementation of the above operations can be found in the previous embodiments and will not be repeated here.

[0202] The computer-readable storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0203] Since the instructions stored in the computer-readable storage medium can execute the steps in any display control method provided in the embodiments of the present application, the beneficial effects that can be achieved by any display control method provided in the embodiments of the present application can be achieved. Please refer to the previous embodiments for details and will not be repeated here.

[0204] The above is a detailed introduction to a display control method, device and computer-readable storage medium provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A display control method, wherein: include: Display a whiteboard interface, wherein the whiteboard interface is used to display the display area currently in the display state in the whiteboard page; In response to a non-drawing operation on the whiteboard interface, determining a current display area in a displayed state in the whiteboard page after the non-drawing operation; Determine a content area containing all drawn content in the whiteboard page; Determine a target area based on the current display area and the content area, where the target area is a minimum area including the target display area and the content area; Determining a control display position of the target area in the preview control based on the control display area of the preview control and the target area; The target area is displayed at the control display position.

2. The display control method according to claim 1, wherein: The step of determining the control display position of the target area in the preview control based on the control display area of the preview control and the target area includes: determining a scaling ratio for displaying the target area in the control display area according to a first size of the target area in the whiteboard page and a second size of the control display area; determining a transformation matrix based on the first size, the second size, and the scaling ratio; A control display position of the target area in the preview control is determined according to the transformation matrix.

3. The display control method according to claim 2, wherein: The first size includes a first width and a first height, the second size includes a second width and a second height, and the step of determining a scaling ratio for displaying the target area in the control display area based on the first size of the target area in the whiteboard page and the second size of the control display area includes: Calculating a ratio of the first width to the second width to obtain a width ratio; Calculating a ratio of the first height to the second height to obtain a height ratio; The width ratio and the height ratio are compared, and the larger ratio is determined as the scaling ratio.

4. The display control method according to claim 3, wherein: The step of determining a transformation matrix based on the first size, the second size, and the scaling ratio includes: Calculating a ratio of the first width to the scaling ratio to obtain a target width of the target area within the control display area; Calculating a ratio of the first height to the scaling ratio to obtain a target height of the target area within the control display area; Calculate half of the difference between the second width and the target width to obtain the target horizontal coordinate of the upper left corner of the target area within the control display area; Calculate half of the difference between the second height and the target height to obtain the target vertical coordinate of the upper left corner of the target area within the control display area; Determine the target horizontal coordinate and the target vertical coordinate as the first coordinate of the upper left corner of the target area in the preview control; A transformation matrix is determined based on the second coordinate of the upper left corner vertex of the target area in the whiteboard page, the first coordinate, and the scaling ratio.

5. The display control method according to claim 4, wherein: The non-drawing operation is a translation operation; The determining of the transformation matrix based on the second coordinate of the upper left corner vertex of the target area on the whiteboard page, the first coordinate, and the scaling ratio includes: Calculating the difference between the target horizontal coordinate and the horizontal coordinate in the second coordinate to obtain a horizontal translation amount; Calculating the difference between the target vertical coordinate and the vertical coordinate in the second coordinate to obtain a longitudinal translation amount; The transformation matrix is determined based on the lateral translation amount and the longitudinal translation amount. The display control method according to claim 4 , wherein: The non-drawing operation is a scaling operation; The determining of the transformation matrix based on the second coordinate of the upper left corner vertex of the target area on the whiteboard page, the first coordinate, and the scaling ratio includes: The transformation matrix is determined as: (the scaling ratio, the abscissa of the second coordinate, the ordinate of the second coordinate).

7. The display control method according to claim 4, wherein: The non-drawing operations include translation and scaling operations; The determining of the transformation matrix based on the second coordinate of the upper left corner vertex of the target area on the whiteboard page, the first coordinate, and the scaling ratio includes: The transformation matrix is determined to be the product of a translation transformation matrix and a scaling transformation matrix.

8. The display control method according to claim 1, wherein: After the step of responding to the non-drawing operation on the whiteboard interface, the method further includes: Determine whether this is the first time a non-drawing operation is received; If it is determined that the non-drawing operation is received for the first time, the content area is drawn and stored in a designated storage area, and the preview control is prohibited from being displayed.

9. The display control method according to claim 8, wherein: The method further includes: if it is determined that this is not the first time that a non-drawing operation is received, then during the process of displaying the target area at the control display position, obtaining a drawn content area from the designated storage area, and displaying the content area at a target position corresponding to the content area in the control display area.

10. The display control method according to claim 1, wherein: The current display area in the preview control is displayed in a specified style. After the step of displaying the target area at the control display position, the method further includes: In response to a non-drawing operation on a current display area displayed in a specified style within the preview control, determining a current position of the current display area in the preview control; Determine an inverse transformation matrix according to the transformation matrix; Determining a changed position of the current display area within the whiteboard page based on the current position and the inverse transformation matrix; The current display area in the whiteboard page is adjusted to the changed position.

11. The display control method according to claim 10, wherein: The determining of an inverse transformation matrix according to the transformation matrix comprises: Perform the inverse operation on the numbers in the translation transformation matrix to obtain the inverse translation transformation matrix.

12. The display control method according to claim 10, wherein: The determining of an inverse transformation matrix according to the transformation matrix comprises: The inverse scaling transformation matrix is obtained by performing a reciprocal operation on the scaling ratio in the scaling transformation matrix.

13. The display control method according to claim 1, wherein: Displaying the target area at the control display position includes: Display each point in the target area within the control display position according to the calculated control display position.

14. The display control method according to claim 1, wherein: The method further includes: after starting the whiteboard application, initializing the preview control; Triggering the preview control to enter the data and status initialization phase; Monitor the life cycle changes of the whiteboard page and register with the whiteboard to perform cleanup when the whiteboard page is closed; After registration is completed, the preview control drawing sub-thread is started and waits for the drawing task; When the drawing sub-thread is finished, the cached Bitmap drawing sub-thread is started and waits for the task of displaying the content area on the cached Bitmap. When the cache Bitmap is started, the initialization of the preview control is completed, and the initialization of the whiteboard is ended.

15. The display control method according to claim 14, wherein: The method further comprises: When the preview control is initialized, the whiteboard calls to start the display process; Obtaining whiteboard page background information, scaling information, and an element drawing snapshot list from the whiteboard page; Generate control drawing information and trigger the preview control drawing process; Draw the snapshot list to the specified position of the cached Bitmap; Update the control state of the preview control, trigger the control drawing sub-thread to refresh the control display, the control drawing sub-thread draws the background, and draws the cached Bitmap to the target area of the preview control. Draw the foreground; An instance of an update preview control is generated and displayed in the preview control.

16. The display control method according to claim 15, wherein: The method further comprises: When the preview control is displayed, calling the update interface to update the control display, hiding the delayed closing task of the preview control, and generating the latest drawing information; Triggering the preview control to update drawing; The drawing child thread draws the background, draws the cached Bitmap to the target area of the preview control, and draws the foreground; Informs the preview control that drawing is finished and the preview control has finished updating the control state.

17. The display control method according to claim 16, wherein: The method further comprises: When non-drawing operations are stopped, the delayed closing interface is called to trigger the preview control to automatically hide after the preset delay time; Trigger the delayed shutdown task; When the delayed preset time task is not canceled, the preview control is hidden.

18. The display control method according to claim 17, wherein: The method further comprises: When non-drawing operations are performed on the current display area in the preview control, the preview control is controlled to handle non-drawing operation events; The preview control removes the automatic hiding task and calculates the latest drawing data; Trigger the preview control to refresh the drawing content, and the preview control drawing sub-thread will draw until the drawing is completed.

19. A computer-readable storage medium, wherein: The computer-readable storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor to execute the steps in the display control method according to any one of claims 1 to 18.

20. A computer device, wherein: The display control method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the steps of the display control method according to any one of claims 1 to 18.

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