zan1456/flutter
1
0
Fork 0
forked from firka/flutter
Code Pull Requests Activity

Update Dartdoc for SceneBuilder#addPlatformView (flutter/engine#6957)

Browse Source
This commit is contained in:
Amir Hardon
2018-11-27 10:03:16 -08:00
committed by GitHub
parent e0fa0cb73c
commit c716627a32
1 changed files with 14 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
engine/src/flutter/lib/ui/compositing.dart
View File

@@ -274,7 +274,20 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
/// Adds a platform view (e.g an iOS UIView) to the scene.
///
/// This is work in progress and is not currently supported on any platform.
/// Only supported on iOS, this is currently a no-op on other platforms.
///
/// On iOS this layer splits the current output surface into two surfaces, one for the scene nodes
/// preceding the platform view, and one for the scene nodes following the platform view.
///
/// ## Performance impact
///
/// Adding an additional surface doubles the amount of graphics memory directly used by Flutter
/// for output buffers. Quartz might allocated extra buffers for compositing the Flutter surfaces
/// and the platform view.
///
/// With a platform view in the scene, Quartz has to composite the two Flutter surfaces and the
/// embedded UIView. In addition to that, on iOS versions greater than 9, the Flutter frames are
/// synchronized with the UIView frames adding additional performance overhead.
void addPlatformView(int viewId, { Offset offset: Offset.zero, double width: 0.0, double height: 0.0}) {
assert(offset != null, 'Offset argument was null');
_addPlatformView(offset.dx, offset.dy, width, height, viewId);