<AWT Dev> [10] Review request for 8166772: Touch keyboard is not shown for text components on a screen touch

Anton Litvinov anton.litvinov at oracle.com
Wed Aug 30 18:51:32 UTC 2017

Hello dear reviewers,

Could anybody please look at this review request?

Thank you,

On 17/08/2017 13:20, Anton Litvinov wrote:
> Hello,
> Could you please review the following fix for the bug.
> Bug: https://bugs.openjdk.java.net/browse/JDK-8166772
> Webrev: http://cr.openjdk.java.net/~alitvinov/8166772/jdk10/webrev.00
> The bug is the fact that, when a user touches any Swing or AWT text 
> component, for example "JTextField", "JTextArea", "TextField", 
> "TextArea", by means of a touch screen on a host with MS Windows 
> 10/8.1/8 OS, the system touch keyboard is not shown automatically. 
> Please find a detailed description of the bug, screenshots depicting 
> the touch keyboard and a compilable test case with Swing/AWT text 
> components in JBS bug record. Also a summary of the done research of 
> the issue with a description of identified approaches for its 
> resolution are reported in my last comment in the bug record.
> On a very abstract level the fix functioning can be presented by the 
> next 3 stages:
> Stage 1.
> The fix adds support of "WM_TOUCH" system window messages to AWT 
> native peer windows through C++ class "AwtComponent". It "processes" 
> "WM_TOUCH" message and marks "java.awt.event.MouseEvent", which is 
> created as a result of handling of the further coming 
> "WM_LBUTTONDOWN", "WM_LBUTTONUP" messages sent by the system in 
> substitution for this "WM_TOUCH" message, by the new private field 
> flag "MouseEvent.causedByTouchEvent".
> Stage 2.
> Then on Java level the fix handles "MouseEvent", "FocusEvent" received 
> only by the instances of "java.awt.TextComponent", 
> "javax.swing.text.TextComponent" in 
> "WToolkit.showOrHideTouchKeyboard()" called from 
> "Component.dispatchEventImpl()" and shows or hides the touch keyboard 
> on "MouseEvent.MOUSE_RELEASED" and "FocusEvent.FOCUS_LOST" events by 
> calling corresponding native methods of "WToolkit" class.
> Stage 3.
> Showing of the touch keyboard is implemented in C++ class "AwtToolkit" 
> and is done by launching the system application "TabTip.exe" which 
> implements the system touch keyboard. This approach is described in 
> the bug record.
> 1. By default all native and Java parts of the fix do not function at 
> all - the fix is disabled. To enable the fix the application should be 
> run with "-Dawt.touchKeyboardAutoShowIsEnabled=true" option. Handling 
> of this new property is implemented in "sun.awt.SunToolkit" class.
> 2. Native parts of the fix functions only on MS Window 8 or later.
> 3. The fix implements automatic showing of the touch keyboard for the 
> following 2 use cases:
>     a.  The user touches the text components using the touch screen.
>     b.  The user does mouse clicks on the text components, while no 
> any keyboard is attached to the host.
> 1. Core of the fix:
>     Native code:  awt_Toolkit.[h/cpp], awt_Component.[h/cpp], 
> awt_MouseEvent.[h/cpp], awt.h
>     Java:  SunToolkit.java, WToolkit.java, Component.java, 
> MouseEvent.java, AWTAccessor.java
> 2. Changes in all remaining Java files are connected with retaining of 
> the flag value "MouseEvent.causedByTouchEvent" during creation of the 
> new instances of "MouseEvent" class based on the original "MouseEvent" 
> instances.
> Work of the fix was verified both in the environment with the real 
> touch screen device and in the environment with the emulated touch 
> screen.
> Thank you,
> Anton

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