Some platform preference changes can trigger the emission of multiple
notifications. For example, when switching from a high-contrast theme on
Windows to the regular theme, the following notifications are emitted (log can
be viewed in `PlatformPreferencesChangedTest`):
changed:
Windows.UIColor.Accent=0x0078d4ff
Windows.SysColor.COLOR_HIGHLIGHTTEXT=0xffffffff
Windows.SysColor.COLOR_WINDOW=0xffffffff
Windows.UIColor.AccentLight1=0x0091f8ff
Windows.SysColor.COLOR_3DFACE=0xf0f0f0ff
Windows.SysColor.COLOR_HOTLIGHT=0x0066ccff
Windows.SysColor.COLOR_WINDOWTEXT=0x000000ff
Windows.SysColor.COLOR_BTNTEXT=0x000000ff
Windows.UIColor.Foreground=0x000000ff
Windows.UIColor.AccentDark1=0x0067c0ff
Windows.UIColor.Background=0xffffffff
Windows.UIColor.AccentLight3=0x99ebffff
Windows.UIColor.AccentLight2=0x4cc2ffff
Windows.SysColor.COLOR_GRAYTEXT=0x6d6d6dff
Windows.SysColor.COLOR_HIGHLIGHT=0x0078d7ff
Windows.UIColor.AccentDark2=0x003e92ff
Windows.UIColor.AccentDark3=0x001a68ff
changed:
-Windows.SPI.HighContrastColorScheme
Windows.SPI.HighContrast=false
changed:
Windows.UIColor.Foreground=0xffffffff
Windows.UIColor.Background=0x000000ff
Notably, the values for Windows.UIColor.Foreground/Background are inconsistent
between the notifications (although they are eventually correct). In general,
only a single notification should be emitted that includes all of the changed
preferences.
This artifact is only visible on Windows. The reason is that changing some
system settings (like high-contrast theme) causes a number of different window
messages to be sent to the application. We should wait for all window messages
to come in, and then aggregate all of the changed preferences into a single
notification.
In order to minimize the delay between changing a system setting and sending
out the notification in JavaFX, the implementation only waits when instructed
to do so by the native toolkit. This allows us to instantly send out
notifications for most changes, but selectively wait a bit for changes where
the native toolkit knows that more changes might be coming in.
-------------
Commit messages:
- add delayed change aggregation
Changes: https://git.openjdk.org/jfx/pull/1810/files
Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1810&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8357067
Stats: 319 lines in 13 files changed: 282 ins; 1 del; 36 mod
Patch: https://git.openjdk.org/jfx/pull/1810.diff
Fetch: git fetch https://git.openjdk.org/jfx.git pull/1810/head:pull/1810
PR: https://git.openjdk.org/jfx/pull/1810
