WO2022087981A1

WO2022087981A1 - Handwriting displaying method and apparatus based on android system, and storage medium

Info

Publication number: WO2022087981A1
Application number: PCT/CN2020/124930
Authority: WO
Inventors: 汪然
Original assignee: 京东方科技集团股份有限公司
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2022-05-05
Also published as: CN115280265A

Abstract

A handwriting displaying method and apparatus based on an Android system, and a storage medium, which are used for solving the technical problem in the prior art of delayed displaying of handwriting. The method comprises: when an application is invoked, sharing a first display buffer area, corresponding to the current display page, to a canvas of a local layer to act as a graphic buffer area of the canvas, wherein the first display buffer area is a display buffer area, in a display buffer, corresponding to the current display page (301); when a user is performing a hand drawing operation, acquiring, in real time, coordinate information corresponding to the hand drawing operation (302); and drawing the coordinate information into the canvas by means of a graphics engine SKIA, and forming and displaying a corresponding hand drawing trajectory (303).

Description

A method, device and storage medium for handwriting display based on Android system

technical field

The present disclosure relates to the field of Android technology, and in particular, to a method, device and storage medium for handwriting display based on an Android system.

Background technique

With the popularization of the electronic whiteboard, the electronic whiteboard can not only meet the meeting communication in daily work, but also conveniently store and print the content of the meeting.

However, when the electronic whiteboard is used in the conference, it is limited by the Android display mechanism, so that there is a certain time consumption in the process of waiting for the vertical synchronization (VSYNC) signal and the buffer application release, and this time When the consumption is reflected on the electronic whiteboard, after the user's finger swipes the screen of the electronic whiteboard, the lines drawn by the electronic whiteboard cannot quickly correspond to the coordinates passed by the finger, resulting in a delayed drawing effect and affecting the user's handwriting experience.

In view of this, how to reduce the delayed display of handwriting has become an urgent technical problem to be solved.

SUMMARY OF THE INVENTION

The present disclosure provides a method, device and storage medium for handwriting display based on an Android system, which are used to solve the technical problem of delayed display of handwriting existing in the prior art.

In the first aspect, in order to solve the above technical problems, the technical solution of a method for displaying handwriting provided by the embodiments of the present disclosure is as follows:

When calling the application, the first display buffer corresponding to the current display page is shared with the canvas of the local layer as the graphics buffer of the canvas; wherein, the first display buffer is the same as the current display buffer in the display buffer. A display buffer corresponding to the display page;

During the period when the user performs the hand-drawing operation, obtain the coordinate information corresponding to the hand-drawing operation in real time;

The coordinate information is drawn into the canvas by the drawing engine SKIA, and the corresponding hand-drawn track is formed and displayed.

In a possible implementation manner, the first display buffer corresponding to the current display page is shared with the canvas of the local layer as the graphics buffer of the canvas, including:

mapping the display cache to a virtual memory corresponding to the application; wherein the display cache includes a plurality of display buffers, and the virtual memory is the same size as the display cache;

determining the first area number of the first display buffer;

Obtain a first virtual area corresponding to the first number from the virtual memory;

The first virtual area is used as the graphics buffer.

A possible implementation is to map the display cache to the virtual memory corresponding to the application, including:

Acquire basic information of the display cache; wherein the basic information includes the size of the display cache;

According to the basic information, create the virtual memory of the same size as the display cache;

The display cache is mapped to the virtual cache.

A possible implementation manner, before the user performs the hand-drawing operation, further includes:

Synchronizing the data in the first display buffer to the remaining display buffers.

A possible implementation is to use the drawing engine SKIA to draw the coordinate information into the canvas to form and display the corresponding hand-drawn trajectory, including:

backing up the data in the first display buffer to the temporary buffer;

When a pressing operation in the hand-drawing operation is captured, the coordinate information is set in the Path object, and transferred to the canvas for trajectory drawing, and when the pressing operation is not captured, the trajectory drawing is ended, The hand-drawn trajectory is obtained.

A possible implementation manner, after the pressing operation is not captured, further includes:

optimizing the hand-drawn trajectory;

Overwrite the second display buffer with the data of the temporary buffer, and notify SurfaceFlinger to synthesize the optimized hand-drawn trajectory into the second display buffer;

Switching the second display buffer to a display buffer corresponding to the current display page, and refreshing the content of the second display buffer to the current display page when the next vertical synchronization signal arrives; wherein , in the display buffer, the second display buffer is the next display buffer of the first display buffer, and the next display buffer of the last display buffer in the display buffer is the display buffer The first display buffer in the cache.

A possible implementation manner, after refreshing the content of the second display buffer to the current display page, further includes:

When no new hand-drawing operation is captured, the temporary buffer is released, and the mapping of the display buffer is ended.

In a second aspect, an embodiment of the present disclosure provides a device for displaying handwriting based on an Android system, including:

The sharing unit is used to share the first display buffer corresponding to the current display page to the canvas of the local layer as the graphics buffer of the canvas when the application is called; wherein, the first display buffer is the display buffer A display buffer corresponding to the currently displayed page in the;

an obtaining unit, configured to obtain coordinate information corresponding to the hand-drawn operation in real time during the period when the user performs the hand-drawn operation;

The drawing unit is used to draw the coordinate information on the canvas by using the drawing engine SKIA, and form and display the corresponding hand-drawn track.

A possible implementation manner, the shared unit is used for:

determining the first area number of the first display buffer;

The first virtual area is used as the graphics buffer.

In a possible implementation manner, the shared unit is also used for:

The display cache is mapped to the virtual cache.

A possible implementation manner, the obtaining unit is further used for:

Before the user performs the hand-drawing operation, the data in the first display buffer is synchronized to the remaining display buffers.

A possible implementation manner, the drawing unit is used for:

backing up the data in the first display buffer to the temporary buffer;

A possible implementation manner, the drawing unit is also used for:

After the pressing operation is not captured, optimizing the hand-drawn trajectory;

A possible implementation manner, the drawing unit is also used for:

After the content of the second display buffer is refreshed to the current display page, when no new hand-drawing operation is captured, the temporary buffer is released, and the mapping of the display buffer is ended.

In a third aspect, an embodiment of the present disclosure further provides a device for displaying handwriting based on an Android system, including:

at least one processor, and

a memory connected to the at least one processor;

Wherein, the memory stores instructions executable by the at least one processor, and the at least one processor executes the method according to the first aspect above by executing the instructions stored in the memory.

In a fourth aspect, an embodiment of the present disclosure further provides a readable storage medium, including:

memory,

The memory is used to store instructions that, when executed by the processor, cause an apparatus including the readable storage medium to perform the method as described in the first aspect above.

Description of drawings

Figure 1 is a schematic diagram of the Android system framework;

Fig. 2 is the flow chart of screen drawing in the Android system;

3 is a flowchart of a method for displaying handwriting provided by an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a mapping display cache provided by an embodiment of the present disclosure;

5 is a schematic diagram of displaying images corresponding to multiple display buffers in a memory when a hand-drawn track is formed according to an embodiment of the present disclosure;

6 is a schematic diagram of an optimized hand-drawn trajectory in a second display buffer provided by an embodiment of the present disclosure;

7 is a schematic diagram 1 of displaying images corresponding to multiple display buffers in a memory when a new hand-drawn track is formed according to an embodiment of the present disclosure;

8 is a schematic diagram 2 of displaying images corresponding to multiple display buffers in memory when a new hand-drawn track is formed according to an embodiment of the present disclosure;

9 is a schematic diagram 3 of displaying images corresponding to multiple display buffers in memory when a new hand-drawn track is formed according to an embodiment of the present disclosure;

10 is a schematic diagram of the final "王" character provided by the embodiment of the present disclosure;

FIG. 11 is a schematic structural diagram of a handwriting display device according to an embodiment of the present disclosure.

Detailed ways

Embodiments of the present disclosure provide a method, device and storage medium for handwriting display based on an Android system, so as to solve the technical problem of delayed display of handwriting existing in the prior art.

In order to better understand the above technical solutions, the technical solutions of the present disclosure will be described in detail below through the accompanying drawings and specific embodiments. It is not intended to limit the technical solutions of the present disclosure, and the embodiments of the present disclosure and the technical features in the embodiments may be combined with each other if there is no conflict.

In order for those skilled in the art to fully understand the solution, the related technologies are briefly introduced before accepting the solution.

Please refer to FIG. 1 for a schematic diagram of the Android system framework.

The Android system includes the APP of the application layer, the local interface (Java Native Interface, JNI), the drawing engine (Skia), libfd_dev.so, and Framebuffer. The underlying Framebuffer is operated through libfd_dev.so to realize reading and writing; the Skia framework is responsible for the drawing of Native handwriting, and the relevant drawing interface is provided to the upper-layer application APP for calling through the JNI mechanism of Android.

Among them, Skia is a low-level graphics, image, animation, scalable vector graphics (Scalable Vector Graphics, SVG), text and other aspects of the graphics library, is the 2D engine of the graphics system in Android. In the Android system, the native layer (Native layer) is written in C/C++ language, which communicates with the application layer (written in Java language, also called Java layer), which is used to process more complex operations and access the operating system. Bottom layer (such as system hardware). Usually, the above Skia is located in the Native layer. The 2D drawing interfaces provided by Android to APP development programmers, such as drawing lines, circles, bitmaps, etc., are JNI encapsulation of the Skia library interface of the native layer (Native layer).

Please refer to FIG. 2 for a flowchart of screen drawing in the Android system.

Step 201: The application sends a registration request to the WMS.

An application (Application, APP) at the application layer sends a request for registering a window to a window management service (WindowManagerService, WMS), so that the WMS divides the application into a window.

Step 202: The WMS sends a request to SurfaceFlinger to allocate a Surface.

WMS sends SurfaceFlinger a request to assign a graphical interface (Surface) to the application according to the registration request.

Step 203: SurfaceFlinger returns allocation information to WMS.

SurfaceFlinger allocates buffers for the application according to the request of WMS, and returns the allocation information to WMS.

Step 204: The WMS returns the Surface object to the application.

The WMS generates the Surface object corresponding to the application according to the allocation information, and returns it to the application. Among them, the Surface object corresponds to the window to be drawn in the APP.

After that, the application draws on the buffer corresponding to the Surface object, and after the drawing is completed, step 105 is performed.

Step 205: The drawing is completed, and the update is notified.

After the application finishes drawing, it notifies SurfaceFlinger to update it so that the drawing result can be displayed on the system screen.

When the display screen is updated, all the windows (Surface objects) of the APP will be superimposed into a bitmap memory with the same size as the screen displayed on the system screen, and written to the Framebuffer. When the VSYNC signal after writing is completed, the arrival of , the Framebuffer is displayed on the screen as the current display buffer, and the rendering update of the display screen is completed. Among them, Linux abstracts the Framebuffer device for user-mode processes to directly write the screen, while the Framebuffer mechanism imitates the function of the graphics card, abstracts the hardware structure of the graphics card, and can directly operate the video memory through the reading and writing of the Framebuffer.

In Android, the VSYNC signal is periodically generated by the underlying HWcomposer. At present, the general mainstream refresh rate is 60 times/second, that is, every 16ms, the VSYNC signal is sent once.

In order to solve the problem of poor fluency of Android's user interface (User Interface, UI), the Android system introduces the design of Triple Buffer and Choreographer, which cooperates with the VSYNC signal to realize the multi-buffer mechanism, that is, only one Framebuffer content is displayed at each moment. On the screen, the cached Framebuffer that is not displayed is applied from the display queue for window drawing. After the VSYNC signal arrives, it is exchanged as a front buffer for display.

In the conference whiteboard system, the main function is to meet the user's demand for handwritten input of the content of the conference discussion. However, due to the above-mentioned Android display mechanism, the drawn window is waiting for the VSYNC signal and the buffer application to be released. cause a certain amount of time consumption. When reflected on the device, that is, after the user's finger swipes across the screen, the drawn line cannot quickly correspond to the coordinates the finger passes through, resulting in a delayed drawing effect and affecting the user's handwriting experience.

In order to solve the above-mentioned technical problems, the technical solutions in the embodiments of the present disclosure adopt the following solutions:

Referring to FIG. 3 , an embodiment of the present disclosure provides a method for displaying handwriting based on an Android system, and the processing process of the method is as follows.

Step 301: When calling the application, share the first display buffer corresponding to the current display page to the canvas of the local layer as a graphics buffer of the canvas; wherein, the first display buffer is the display buffer corresponding to the current display page. of a display buffer.

The picture currently displayed on the screen is the current display page, and the first display buffer is a display buffer in the display buffer corresponding to the plane. Currently, what is displayed on the screen is a bitmap corresponding to the data in the first display buffer.

Share the first display buffer corresponding to the current display page to the canvas (ie SkCanvas) of the native layer (Native layer) as the graphics buffer of the canvas (ie SkBitmap), which can be achieved by the following methods: mapping the display buffer to the application Corresponding virtual memory; wherein, the display cache includes a plurality of display buffers, and the virtual memory and the display cache have the same size; determine the first area number of the first display buffer; obtain the first virtual memory corresponding to the first number from the virtual memory area; use the first virtual area as a graphics buffer.

If the electronic device adopts the double-buffering mechanism, the number of display buffers in the display buffer is 2, and if the electronic device adopts the multi-buffering mechanism, the display buffers in the display buffer may be, for example, three or more.

Mapping the display cache to the virtual memory corresponding to the application can be achieved in the following ways: obtain the basic information of the display cache; the basic information includes the size of the display cache; create a virtual memory of the same size as the display cache according to the basic information; Caches are mapped to virtual caches.

In the Android system, you can open the /dev/graphics/fb0 device by calling the libfbdev.so dynamic library, obtain the size of the display buffer, including the size information of the display buffer, etc., and map it to the virtual memory of the application layer through the mmap function. The application layer pointer addr maps the display buffer to the virtual buffer and encapsulates it in the canvas (SkCanvas) as the graphics buffer (SkBitmap) of the canvas (SkCanvas), so that the drawing engine SKIA can be used to perform hand-painting operations in the canvas (SkCanvas).

Please refer to FIG. 4 , a schematic diagram of a mapping display cache provided by an embodiment of the present disclosure. According to the design of TripleBuffer, the display cache includes 3 consecutive display buffers, so the virtual memory also includes 3 consecutive virtual areas. In Figure 4, the pointer addr is used to address the virtual memory. The 3 virtual memory in the virtual memory The first address of the area is indicated by addr1, addr2, and addr3 in sequence.

After that, you can allocate the canvas of the Native layer by calling the Skia-related dynamic library, and encapsulate the display cache mapped to the virtual memory through the SkBitmap object and place it in the canvas object.

Since the display buffer includes multiple display buffers, the first display buffer (front buffer) corresponding to the current display page will be switched among the multiple display buffers according to the drawing refresh indicated by the application. In order to ensure the graphics buffer used by the canvas The area is the first display buffer, and the number of the first display buffer needs to be obtained accurately.

To determine the first number of the first display buffer, a shared memory can be set, so that when the display buffer is switched, the display cache writes the first number into the shared memory, and the local layer reads the first number from the shared memory. A number is obtained, and the first virtual area corresponding to the first number is obtained from the virtual memory instead of using it as a graphics buffer of the canvas. In this way, it is possible to directly draw a simple 2D image in the video memory cache, and ensure that it is consistent with the trajectory drawn by calling Skia.

After the first display buffer corresponding to the current display page is shared with the canvas of the local layer, step 302 can be executed.

Step 302: During the period when the user performs the hand-drawing operation, obtain the coordinate information corresponding to the hand-drawing operation in real time.

The hand-drawn operation can be an operation performed by a finger directly on the screen, or an operation performed by a user on the screen with a hand-drawn pen.

Before the user performs the hand-drawing operation, the data in the first display buffer can also be synchronized to the remaining display buffers.

Since the present disclosure bypasses the Choreographer mechanism of the Android system for drawing, before performing the hand-drawing operation, by synchronizing the data in the first display buffer to the remaining display buffers, all display buffers in the display buffer can be made current. Displays the page's data.

The coordinate information corresponding to the hand-drawing operation can be obtained by calling the callback function, and after obtaining the coordinate information of the hand-drawing operation, step 303 can be executed.

Step 303: Use the drawing engine SKIA to draw the coordinate information on the canvas to form and display the corresponding hand-drawn track.

Use the drawing engine SKIA to draw the coordinate information into the canvas to form and display the corresponding hand-drawn trajectory, which can be achieved in the following ways:

Back up the data in the first display buffer to the temporary buffer; when the pressing operation in the hand-painting operation is captured, set the coordinate information in the Path object and transfer it to the canvas for trajectory drawing. If the pressing operation is not captured When the trajectory drawing is ended, the hand-drawn trajectory is obtained. Since the first display buffer has been mapped to the display buffer before, the above hand-drawing operation is equivalent to drawing in the first display buffer, so that the hand-drawn trajectory displayed in real time can be quickly followed by the hand-drawn operation. .

Please refer to FIG. 5 , which is a schematic diagram of displaying images corresponding to multiple display buffers in the memory when forming a hand-drawn track according to an embodiment of the present disclosure. Assuming that all the images corresponding to the display buffers are blank images at the beginning, the images numbered 1 to 3 in Figure 5 are the images corresponding to the data of the three display buffers in the display buffer, and the arrows point to the first display buffer corresponding to image (the same below), that is, image 1 is the image displayed on the currently displayed page, and the other two images are not currently displayed. When the user performs a hand-drawing operation, a "one" track is formed in FIG. 1 .

After the pressing operation is not captured (that is, a hand-drawn trajectory is completed), the hand-drawn trajectory needs to be converted into a line that conforms to the system standard for display, which can be achieved in the following ways:

The application layer optimizes the hand-drawn track, overwrites the second display buffer with the data of the temporary buffer, and informs SurfaceFlinger to synthesize the optimized hand-drawn track into the image corresponding to the second display buffer; switch the second display buffer to The display buffer corresponding to the current display page, and when the next vertical synchronization signal arrives, refresh the content of the second display buffer to the current display page; wherein, in the display buffer, the second display buffer is the first display buffer The next display buffer in the display buffer is the first display buffer in the display buffer.

Please refer to FIG. 6 , which is a schematic diagram of an optimized hand-drawn trajectory in the second display buffer provided by an embodiment of the present disclosure. After the hand-drawn track shown in FIG. 5 is formed, the image 2 in FIG. 6 (ie, the image corresponding to the second display buffer area) is displayed on the current display page by the above method.

After the content of the second display buffer is flushed to the current display page, when no new hand-drawing operation is captured, the temporary buffer is released, and the mapping of the display buffer is ended. This keeps the system stable.

Suppose the user draws a word "王" on the screen, please refer to Figure 5 and Figures 7 to 10. FIG. 7 is a schematic diagram 1 of displaying images corresponding to multiple display buffers in memory when a new hand-drawn track is formed according to an embodiment of the present disclosure, and FIG. 8 shows a plurality of images in memory when a new hand-drawn track is formed according to an embodiment of the present disclosure. Schematic diagram 2 of images corresponding to each display buffer, FIG. 9 is a schematic diagram 3 of displaying images corresponding to multiple display buffers in the memory when a new hand-drawn track is formed according to an embodiment of the present disclosure, and FIG. 10 is a final schematic diagram provided by an embodiment of the present disclosure. Schematic diagram of the word "King".

After the user performs the first hand-drawing operation, the first "one" in the word "王" is formed (referred to as hand-drawn track 1), as shown in Figure 5, when the hand-drawn track 1 is completed, the application layer optimizes the hand-drawn track 1 , get the optimized hand-drawn track 1, then overwrite the data in the second display buffer with the data in the temporary buffer (the data of the first display buffer backed up before drawing the hand-drawn track 1), and notify SurfaceFlinger that the optimized The hand-drawn track 1 is synthesized into the image corresponding to the second display buffer, the second display buffer is switched to the display buffer corresponding to the current display page, and after the arrival of the next vertical synchronization signal, the drawing refresh is completed, and the second display buffer is The data in the display buffer is refreshed to the current display page currently displayed on the screen.

Assuming that the user clicks back on the screen at this time, and performs a new hand-drawing operation on the screen, forming a hand-drawn trajectory 2 as shown in Figure 7 (that is, the second "one" in the word "王"), then the screen will be displayed on the screen. At the same time, the optimized hand-drawn track 1 and hand-drawn track 2 are displayed. When the hand-drawn track 2 is completed, the application layer optimizes the hand-drawn track 2 to obtain the optimized hand-drawn track 2, and then uses the data in the temporary buffer (the data in the second display buffer that was backed up before drawing the hand track 2, i.e. Image 2 in 6) Overwrite the data in the third display buffer, and notify SurfaceFlinger to synthesize the optimized hand-drawn track 2 into the image corresponding to the third display buffer, and switch the third display buffer to be the same as the current display. The display buffer corresponding to the page, and after the arrival of the next vertical synchronization signal, the drawing refresh is completed, and the data in the third display buffer is refreshed to the current display page currently displayed on the screen.

Then, the user clicks back on the screen and performs a new hand-drawn operation on the screen to form the hand-drawn track 3 (ie, "︱" in the word "王") as shown in Figure 8. At this time, the optimized image will be displayed on the screen at the same time. The hand-drawn trajectory 1 and the optimized hand-drawn trajectory 2, and the hand-drawn trajectory 3. When the hand-drawn track 3 is completed, the application layer optimizes the hand-drawn track 3 to obtain the optimized hand-drawn track 3, and then overwrites it with the data in the temporary buffer (the data in the third display buffer that was backed up before drawing the hand track 3). The data in the first display buffer, and notify SurfaceFlinger to synthesize the optimized hand-drawn track 3 into the image corresponding to the first display buffer, and switch the first display buffer to the display buffer corresponding to the current display page, And after the arrival of the next vertical synchronization signal, the drawing refresh is completed, and the data in the first display buffer is refreshed to the current display page currently displayed on the screen.

Finally, the user clicks back on the screen and performs a new hand-drawn operation on the screen to form a hand-drawn track 4 as shown in Figure 9 (that is, the third "one" in the word "王"). Display the optimized hand-drawn track 1 to the optimized hand-drawn track 3, and the hand-drawn track 4, forming the word "king". When the hand-drawn track 4 is completed, the application layer optimizes the hand-drawn track to obtain the optimized hand-drawn track 4, and then uses the data in the temporary buffer (the data of the first display buffer backed up before drawing the hand track 4) to overwrite the second Display the data in the buffer, and notify SurfaceFlinger to synthesize the optimized hand-drawn track 4 into the image corresponding to the second display buffer, switch the second display buffer to the display buffer corresponding to the current display page, and in the next After a vertical synchronization signal arrives, the drawing refresh is completed, and the data in the second display buffer is refreshed to the current display page currently displayed on the screen, as shown in FIG. 10 .

It should be noted that, in order to determine which track in the schematic diagram 5-10 is the track being drawn by the user, the user's "hand" is indicated where the track is being drawn, and the "hand" is not actually a component of the image. In order to facilitate the distinction, thin lines are used to indicate the hand-drawn trajectory, and thick lines are used to indicate the optimized hand-drawn trajectory.

The above method can be used not only for electronic whiteboards, but also for electronic devices such as televisions and mobile phones.

Based on the same inventive concept, an embodiment of the present disclosure provides a device for displaying handwriting based on an Android system. For the specific implementation of the method for displaying handwriting in the device, please refer to the description of the method embodiment section, and the repeated parts will not be repeated. Referring to Figure 11, the device includes:

The sharing unit 1101 is used to share the first display buffer corresponding to the current display page to the canvas of the local layer as the graphics buffer of the canvas when the application is called; wherein, the first display buffer is the display buffer a display buffer corresponding to the currently displayed page in the cache;

an obtaining unit 1102, configured to obtain coordinate information corresponding to the hand-drawn operation in real time during the period when the user performs the hand-drawn operation;

The drawing unit 1103 is configured to use the drawing engine SKIA to draw the coordinate information into the canvas to form and display the corresponding hand-drawn track.

In a possible implementation manner, the sharing unit 1101 is used for:

determining the first area number of the first display buffer;

The first virtual area is used as the graphics buffer.

In a possible implementation manner, the sharing unit 1101 is further used for:

The display cache is mapped to the virtual cache.

In a possible implementation manner, the obtaining unit 1102 is further configured to:

In a possible implementation manner, the drawing unit 1103 is used for:

backing up the data in the first display buffer to the temporary buffer;

In a possible implementation manner, the drawing unit 1103 is also used for:

Covering the second display buffer with the data of the temporary buffer, and informing SurfaceFlinger to synthesize the optimized hand-drawn trajectory into the image corresponding to the second display buffer;

In a possible implementation manner, the drawing unit 1103 is also used for:

Based on the same inventive concept, an embodiment of the present disclosure provides a device for displaying handwriting based on an Android system, including: at least one processor, and

a memory connected to the at least one processor;

Wherein, the memory stores instructions executable by the at least one processor, and the at least one processor executes the above-described handwriting display method by executing the instructions stored in the memory.

Based on the same inventive concept, an embodiment of the present disclosure also provides a readable storage medium, including:

memory,

The memory is used to store instructions, and when the instructions are executed by the processor, make the apparatus including the readable storage medium complete the above-described handwriting display method.

As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, embodiments of the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media having computer-usable program code embodied therein, including but not limited to disk storage, CD-ROM, optical storage, and the like.

Embodiments of the present disclosure are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit and scope of the present disclosure. Thus, provided that these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to cover such modifications and variations.

Claims

A method for displaying handwriting based on an Android system, comprising:

When calling the application, the first display buffer corresponding to the current display page is shared with the canvas of the local layer as the graphics buffer of the canvas; wherein, the first display buffer is the same as the current display buffer in the display buffer. A display buffer corresponding to the display page;

During the period when the user performs the hand-drawing operation, obtain the coordinate information corresponding to the hand-drawing operation in real time;

The coordinate information is drawn into the canvas by the drawing engine SKIA, and the corresponding hand-drawn track is formed and displayed.
The method of claim 1, wherein sharing the first display buffer corresponding to the current display page to the canvas of the local layer as the graphics buffer of the canvas, comprising:

mapping the display cache to a virtual memory corresponding to the application; wherein the display cache includes a plurality of display buffers, and the virtual memory is the same size as the display cache;

determining the first area number of the first display buffer;

Obtain a first virtual area corresponding to the first number from the virtual memory;

The first virtual area is used as the graphics buffer.
The method of claim 2, wherein mapping the display cache to the virtual memory corresponding to the application comprises:

Acquire basic information of the display cache; wherein the basic information includes the size of the display cache;

According to the basic information, create the virtual memory of the same size as the display cache;

The display cache is mapped to the virtual cache.
The method of claim 1, wherein before the user performs the hand-drawing operation, further comprising:

Synchronizing the data in the first display buffer to the remaining display buffers.
The method according to any one of claims 1-4, wherein the coordinate information is drawn into the canvas by a drawing engine SKIA to form and display a corresponding hand-drawn track, comprising:

backing up the data in the first display buffer to the temporary buffer;

When a pressing operation in the hand-drawing operation is captured, the coordinate information is set in the Path object, and transferred to the canvas for trajectory drawing, and when the pressing operation is not captured, the trajectory drawing is ended, The hand-drawn trajectory is obtained.
The method of claim 5, wherein after the pressing operation is not captured, further comprising:

optimizing the hand-drawn trajectory;

Covering the second display buffer with the data of the temporary buffer, and informing SurfaceFlinger to synthesize the optimized hand-drawn trajectory into the image corresponding to the second display buffer;

Switching the second display buffer to a display buffer corresponding to the current display page, and refreshing the content of the second display buffer to the current display page when the next vertical synchronization signal arrives; wherein , in the display buffer, the second display buffer is the next display buffer of the first display buffer, and the next display buffer of the last display buffer in the display buffer is the display buffer The first display buffer in the cache.
The method of claim 6, wherein after refreshing the content of the second display buffer to the current display page, the method further comprises:

When no new hand-drawing operation is captured, the temporary buffer is released, and the mapping of the display buffer is ended.
A device for displaying handwriting based on an Android system, comprising:

The sharing unit is used to share the first display buffer corresponding to the current display page to the canvas of the local layer as the graphics buffer of the canvas when the application is called; wherein, the first display buffer is the display buffer A display buffer corresponding to the currently displayed page in the;

an obtaining unit, configured to obtain coordinate information corresponding to the hand-drawn operation in real time during the period when the user performs the hand-drawn operation;

The drawing unit is used for drawing the coordinate information into the canvas by using the drawing engine SKIA to form and display the corresponding hand-drawn track.
A device for displaying handwriting based on an Android system, comprising:

at least one processor, and

a memory connected to the at least one processor;

Wherein, the memory stores instructions executable by the at least one processor, and the at least one processor executes the method according to any one of claims 1-7 by executing the instructions stored in the memory.
A readable storage medium comprising a memory,

The memory is used to store instructions that, when executed by a processor, cause an apparatus including the readable storage medium to perform the method of any one of claims 1-7.