Widget state machine facing ARINC661 protocol

Abstract

The invention discloses a Widget state machine oriented to an ARINC661 protocol. The Widget state machine comprises a domain recognition algorithm and a context management algorithm. The domain identification algorithm is used for executing a traversal process of a widget tree and identifying whether domain change occurs, and the context management algorithm manages contexts according to an identification result of the domain identification algorithm, and comprises the following steps: (1) entering a sub-domain, putting an original current domain context into a stack top for storage, calculating by an atomic domain context to obtain a new current domain context, and storing the new current domain context in the stack top; calculating and updating the context of the sub-domain according to the attribute of the sub-domain which is being accessed in the new current domain; (2) moving in the domain, keeping the context of the current domain unchanged, and calculating and updating the context of the subdomain according to the attribute of the subdomain which is being accessed in the current domain; and (3) returning to the upper layer domain, and popping the context at the top of the stack to recover the context in the stack to the context of the upper layer domain. According to the invention, the concept of'domain 'is introduced, so that the unified management of the Widget context is realized.

Description

Technical Field

[0001] The invention belongs to the field of integrated civil aircraft avionics system design, and relates to the design and development of a cockpit display system based on the ARINC661 protocol, and in particular to a Widget state machine oriented to the ARINC661 protocol, which automatically manages context. Background Art

[0002] As one of the main human-machine interaction interfaces, the cockpit display system not only displays the current flight parameters, engine status, crew warnings and other important information of the aircraft in real time, but also receives the interactive operation instructions of the pilot on the display interface, which puts forward certain requirements on the operating efficiency and reliability of the cockpit display system. With the continuous development of avionics systems and the introduction of various new sensors, the picture information displayed by the cockpit display system is becoming more and more complex. In order to meet the gradually expanding functional requirements, the ARINC661 protocol may need to be appropriately expanded, which requires the cockpit display system to have good scalability.

[0003] The ARINC661 protocol defines the composition of the display screen, which can be abstracted as follows: Figure 1 The tree structure shown: An independent display unit is called a DU (Display Unit). The DU can be divided into several non-overlapping Windows. In each Window, several Layers are stacked in a certain order. Each Layer is composed of several Widgets with a hierarchical relationship. In the hierarchical relationship of Widgets, the direct superior is called the "parent Widget", the direct subordinate is called the "child Widget", and the same level is called the "brother Widget". A Widget will only have one parent Widget, but can have multiple child Widgets and brother Widgets. The properties of a Widget usually determine the corresponding properties of its child Widgets. For example, when a Widget is invisible, its child Widgets are also invisible. The ARINC661 protocol defines a special Widget called Connector, such as Figure 2 As shown, a Connector links a Layer, and its function is to make the Widget in the linked Layer a child Widget of the Widget to which the Connector belongs.

[0004] In the cockpit display system, the A661Server software is responsible for drawing the display screen. The widget is the smallest functional unit of the display screen. Different types of widgets have different appearances and functions. Coordinates, visibility, interactivity, display priority, interaction priority, cut box and other attributes will affect the appearance and function of the widget. These attributes constitute the drawing state of the widget, called "context". All sub-widgets of a widget share the same context. In the traditional implementation method, for a widget, the context of each of its sub-widgets needs to be set separately, that is, the same context is set multiple times, which is inefficient; for a widget, the drawing function of its sub-widget needs to be recursively called, and the connector also needs to recursively call the drawing function of the linked layer. When the display screen is more complex, it is easy to generate multi-layer recursive nesting, and there is a risk of recursive call stack overflow, resulting in reduced reliability of the entire display system; different types of widgets may have similar functions, and these complex functions are repeatedly implemented, which has the disadvantages of low code reuse rate and poor scalability. Therefore, it is very necessary to optimize the management strategy of the Widget context. Summary of the invention

[0005] The purpose of the invention is to provide a widget state machine for ARINC661 protocol, to automatically manage widget context in a unified manner, thereby improving the operating efficiency of a cockpit display system and enhancing the reliability and scalability of the cockpit display system.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A widget state machine for ARINC661 protocol, including domain identification algorithm and context management algorithm;

[0008] The domain recognition algorithm is used to perform the traversal process of the widget tree and recognize whether a domain change occurs during the traversal process. The recognition result is recorded as the next moving direction, including: entering a subdomain, moving within a domain, and returning to the upper domain;

[0009] The context management algorithm cooperates with the domain recognition algorithm to manage the context according to the recognition result of the domain recognition algorithm, that is, the next moving direction, including:

[0010] (1) Enter the subdomain, put the original current domain context on the top of the stack for storage, calculate the new current domain context from the atomic domain context, and then calculate and update the subdomain context based on the attributes of the subdomain being accessed in the new current domain;

[0011] (2) Intra-domain movement, the current domain context remains unchanged, and the subdomain context is calculated and updated based on the attributes of the subdomain being visited in the current domain;

[0012] (3) Return to the upper domain, pop the top context of the stack and restore the stack to the context of the upper domain.

[0013] Preferably, the domain identification algorithm adopts a depth-first pre-order traversal.

[0014] Furthermore, the Widget state machine also includes a context inheritance algorithm. The context inheritance algorithm uses a context storage table to implement context preservation and restoration. When executing to the inherited domain, the context inheritance algorithm changes certain context attributes of the inherited domain and saves them in the storage table, and records the corresponding context id; when executing to the inheriting domain, according to the context id, the context of the inherited domain is restored from the storage table as the context of the inheriting domain.

[0015] Furthermore, the widget state machine for the ARINC661 protocol also includes an extensible module, which encapsulates specific widget functions into independent modules, and starts the independent module when entering a certain domain, thereby realizing the corresponding functions in the current domain.

[0016] The beneficial effects of the present invention are:

[0017] The present invention automatically manages the widget context through the widget state machine. Compared with the traditional implementation method, the unified management of the widget context is achieved by introducing the concept of "domain". For a widget, you only need to care about its internal logic, and you don't have to set contexts for all its child widgets, which effectively improves the operating efficiency of the display system; for a widget, you don't have to recursively call the drawing function of its child widgets, which removes the recursive mechanism, reduces the risk of stack overflow, and enhances the reliability of the cockpit display system; specific widget functions are implemented by corresponding modules and act on widgets through domains, which improves code reuse, reduces maintenance costs, and enhances the scalability of the display system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram showing the composition of the display screen.

[0019] Figure 2 This is a Connector example.

[0020] Figure 3 is an example of a domain.

[0021] Figure 4 is an example of an inherited domain.

[0022] Figure 5 This is the drawing process of one DU and one cycle screen. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0024] The widget state machine for the ARINC661 protocol shown in this embodiment automatically manages the widget context, and its core is the concept of "domain". All child widgets of a widget share the same context, which constitutes the context scope of the widget, referred to as "domain". In particular, the domain composed of all Windows, the domain composed of all Layers, and the domain composed of all Widgets are called DU domain, Window domain, and Layer domain, respectively. Connector implements context inheritance, and the domain of the linked Layer will inherit the context of the domain where the Connector is located. The former is called the inheriting domain, and the latter is called the inherited domain. The context of the domain is determined by the properties of the Widget (or other containers, such as Window, etc.) to which the domain belongs.

[0025] See also Figure 3 As shown in the domain, assuming that the sub-Widgets of Widget#1 are being traversed at this time, the "current domain" is the domain of Widget#1, and all the widgets in the solid-line box belong to the current domain. Their context is determined by the properties of Widget#1. When traversing to Widget#2, the domain of Widget#2 is called the "subdomain" of the current domain, and the widgets in the dotted-line box belong to the subdomain. Their context is further determined by the properties of Widget#2 based on the current domain. See Figure 4 In the inheritance domain shown, domain #1 is the inherited domain and domain #2 is the inheriting domain. When drawing Layer B, domain #2 will inherit the context of domain #1.

[0026] The Widget state machine for the ARINC661 protocol shown in this embodiment includes a domain identification algorithm, a context management algorithm, a context inheritance algorithm and an extensible module, and realizes automatic management of context in conjunction with the traversal process of the Widget.

[0027] 1. Domain Identification Algorithm

[0028] The domain recognition algorithm is used to perform the traversal process of the widget tree, and to identify whether a domain change occurs during the traversal process, and to record the recognition result as the next moving direction, including: entering a subdomain (DOWN), moving within a domain (RIGHT), and returning to the upper domain (UP).

[0029] The domain identification algorithm uses the depth of the domain to indicate the level of the current domain: the DU domain depth is 0, the Window domain depth is 1, the Layer domain depth is 2, and the Widget domain depth is an integer greater than or equal to 3. The domain identification algorithm is initially in the DU domain.

[0030] The domain identification algorithm uses a depth-first pre-order traversal. During the traversal, there are three situations in which the domain changes:

[0031] (1) Enter the subdomain, the direction is DOWN, and the domain depth increases by 1;

[0032] (2) Move within the domain, the direction is RIGHT, and the domain depth remains unchanged;

[0033] (3) Return to the upper domain, the direction is UP, and the domain depth is reduced by 1.

[0034] (II) Context Management Algorithm

[0035] The context management algorithm cooperates with the domain recognition algorithm to manage the context according to the recognition result of the domain recognition algorithm, that is, the next moving direction, including the preservation, restoration and calculation of the context.

[0036] The context management algorithm uses the "stack" data structure to save and restore the context, ensuring that the Widget state machine can maintain the change track of the domain and then accurately return to the upper domain.

[0037] The current domain context is recorded as CurrentState, and the domain context of the Widget being accessed in the current domain (that is, the subdomain of the current domain) is recorded as SubState.

[0038] Corresponding to the recognition results of the domain recognition algorithm, the context management algorithm will perform three operations:

[0039] (1) The direction is DOWN. The DOWN operation is performed, and the original current domain context CurrentState is put on the top of the stack for storage. The new current domain context CurrentState is calculated from the original SubState, and then the SubState is calculated and updated according to the properties of the Widget being accessed in the new current domain. At this time, the stack retains the context of all domains between the upper domain and the top domain.

[0040] (2) The direction is RIGHT. The RIGHT operation is performed. The current domain context CurrentState remains unchanged. SubState is calculated and updated according to the properties of the Widget being accessed in the current domain.

[0041] (3) The direction is UP. The UP operation is executed to pop the context at the top of the stack and restore it to the CurrentState of the upper domain.

[0042] (III) Context inheritance algorithm

[0043] The widget state machine allows a domain A to inherit the context of another domain B without being restricted by the widget hierarchy. Domain A is called the inheriting domain, and domain B is called the inherited domain. When entering the inherited domain, the widget state machine updates the context, saves the context, and binds the context id to the corresponding inheriting domain. When drawing the inheriting domain, the context is restored to achieve context inheritance.

[0044] Specifically, the context inheritance algorithm includes updating, saving and restoring the context, and a context storage table is used to implement the saving and restoring of the context.

[0045] (1) Context update: When A661server executes to the inherited domain, it changes some context attributes of the inherited domain. For example, it opens up new display space and interaction space to ensure the correctness of the display priority and interaction priority of the inherited domain;

[0046] (2) Context preservation: Save the context of the inherited domain after the change in the storage table and record the corresponding context id;

[0047] (3) Context recovery: When A661server executes to the inheritance domain, it recovers the context of the inherited domain from the storage table according to the context id as the context of the inheritance domain.

[0048] (IV) Expandable modules

[0049] The widget state machine can be appropriately extended by encapsulating specific widget functions into independent modules (such as widget position refresh, widget scrolling, etc.), allowing the module to be started when entering a certain domain, thereby implementing the corresponding functions in the current domain.

[0050] Below through Figure 5 The flowchart shown in the figure describes in detail the process of A661Server software drawing a periodic screen for a DU based on the Widget state machine:

[0051] 1. The A661Server software initializes the Widget state machine, sets the domain depth to 0, that is, in the DU domain, and initializes the current context CurrentState.

[0052] 2. The domain identification algorithm traverses all Windows. Since it is currently in the DU domain, for each Window, the context management algorithm is called to perform the RIGHT operation to update the SubState. Then all Layers in the Window are traversed to complete the drawing of the Window domain.

[0053] 3. For each layer, if the layer is not a linked layer, call the context management algorithm, perform the DOWN operation, enter the Window domain to access the layer, or perform the RIGHT operation to access the next layer; otherwise, for the linked layer, call the context inheritance algorithm to restore the context of the inherited domain as the context of the linked layer. Then start drawing the current layer, use the pre-order traversal algorithm to traverse all the widgets in the layer domain. In this process, the next step of the traversal algorithm is given according to the domain identification algorithm, and the context management algorithm is called to perform the corresponding operation, so as to draw the corresponding widget in the correct context environment. In particular, if a widget sets the flag of its own domain extension function to true, when the domain identification algorithm traverses to the domain, the context management algorithm detects that the flag is true, and then it will search whether there is a corresponding extension function module. If it exists, it will call the module to complete the function. If it does not exist, the function is skipped, and it is determined whether to record an error according to the requirements. If the currently drawn widget is a Connector, the context of the inherited domain should be updated and saved during its drawing process.

[0054] 4. If all Layers in the current Window are drawn, the context management algorithm is called, the UP operation is performed, and the DU domain is returned.

[0055] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A Widget state machine for ARINC661 protocol, characterized in that Contains domain identification algorithm and context management algorithm; The domain recognition algorithm is used to perform the traversal process of the widget tree and recognize whether a domain change occurs during the traversal process. The recognition result is recorded as the next moving direction, including: entering a subdomain, moving within a domain, and returning to the upper domain; The context management algorithm cooperates with the domain recognition algorithm to manage the context according to the recognition result of the domain recognition algorithm, that is, the next moving direction, including: (1) Enter the subdomain, put the original current domain context on the top of the stack for storage, calculate the new current domain context from the atomic domain context, and then calculate and update the subdomain context based on the attributes of the subdomain being accessed in the new current domain; (2) Intra-domain movement, the current domain context remains unchanged, and the subdomain context is calculated and updated based on the attributes of the subdomain being visited in the current domain; (3) Return to the upper domain, pop the top context of the stack and restore the stack to the context of the upper domain.

2. A Widget state machine for ARINC661 protocol according to claim 1, characterized in that The domain identification algorithm uses a depth-first pre-order traversal.

3. A Widget state machine for ARINC661 protocol according to claim 1, characterized in that It also includes a context inheritance algorithm, which uses a context storage table to implement context preservation and restoration. When executing to the inherited domain, the context inheritance algorithm changes certain context attributes of the inherited domain and saves them in the storage table, and records the corresponding context id; when executing to the inheriting domain, the context of the inherited domain is restored from the storage table as the context of the inheriting domain according to the context id.

4. A Widget state machine for ARINC661 protocol according to claim 1, characterized in that It also includes extensible modules, which encapsulate specific Widget functions into independent modules. When entering a certain domain, the independent module is started to implement the corresponding functions in the current domain.

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