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3rdparty/kddockwidgets/docs/book/src/misc_impl_details.md

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+# Event Filters
+
+Since KDDW works with non-Qt, we can't use Qt event filters directly, so we added an abstraction layer.<br>
+Event filters implement `EventFilterInterface`.
+For Qt, we have a `GlobalEventFilter` class, which calls `qGuiApp->installEventFilter`, then forwards events
+to all registered `EventFilterInterface`.
+
+We have the following global event filters:
+
+- DockRegistry singleton
+  Catches expose events to maintain floating window z-order.
+  Catches clicking on a MDI dock widget, to raise it.
+  For hiding the auto-hide sidebar overlay when clicking elsewhere.
+
+- FallbackMouseGrabber
+  For platforms that don't support grabbing the mouse. Mostly for QtQuick to workaround bugs.
+
+- Some wayland code
+
+- WidgetResizeHandler when used by MDI, or if EGLFS
+  For resizing MDI dock widgets when mouse goes near borders.
+
+
+# mdi raise()
+
+Clicking on a MDI dockwidget will raise it.<br>
+This is tested by `tst_mdiZorder()`.<br>
+Actual raising is done by `DockRegistry::onMouseButtonPress()`, which is called by our global event filter.