Summary:
Remove layout-only views. Works by checking properties against a list of known properties that only affect layout. The `RCTShadowView` hierarchy still has a 1:1 correlation with the JS nodes.
This works by adjusting the tags and indices in `manageChildren`. For example, if JS told us to insert tag 1 at index 0 and tag 1 is layout-only with children whose tags are 2 and 3, we adjust it so we insert tags 2 and 3 at indices 0 and 1. This keeps changes out of `RCTView` and `RCTScrollView`. In order to simplify this logic, view moves are now processed as view removals followed by additions. A move from index 0 to 1 is recorded as a removal of view at indices 0 and 1 and an insertion of tags 1 and 2 at indices 0 and 1. Of course, the remaining indices have to be offset to take account for this.
The `collapsible` attribute is a bit of a hack to force `RCTScrollView` to always have one child. This was easier than rethinking out the logic there, but we could change this later.
Summary:
Remove layout-only views. Works by checking properties against a list of known properties that only affect layout. The `RCTShadowView` hierarchy still has a 1:1 correlation with the JS nodes.
This works by adjusting the tags and indices in `manageChildren`. For example, if JS told us to insert tag 1 at index 0 and tag 1 is layout-only with children whose tags are 2 and 3, we adjust it so we insert tags 2 and 3 at indices 0 and 1. This keeps changes out of `RCTView` and `RCTScrollView`. In order to simplify this logic, view moves are now processed as view removals followed by additions. A move from index 0 to 1 is recorded as a removal of view at indices 0 and 1 and an insertion of tags 1 and 2 at indices 0 and 1. Of course, the remaining indices have to be offset to take account for this.
The `collapsible` attribute is a bit of a hack to force `RCTScrollView` to always have one child. This was easier than rethinking out the logic there, but we could change this later.
@public
Test Plan: There are tests in `RCTUIManagerTests.m` that test the tag- and index-manipulation logic works. There are various scenarios including add-only, remove-only, and move. In addition, two scenario tests verify that the optimization works by checking the number of views and shadow views after various situations happen.
Summary:
Simply add an `onLayout` callback to a native view component, and the callback
will be invoked with the current layout information when the view is mounted and
whenever the layout changes.
The only limitation is that scroll position and other stuff the layout system
isn't aware of is not taken into account. This is because onLayout events
wouldn't be triggered for these changes and if they are desired they should be
tracked separately (e.g. with `onScroll`) and combined.
Also fixes some bugs with LayoutAnimation callbacks.
@public
Test Plan:
- Run new LayoutEventsExample in UIExplorer and see it work correctly.
- New integration test passes internally (IntegrationTest project seems busted).
- New jest test case passes.
{F22318433}
```
2015-05-06 15:45:05.848 [info][tid:com.facebook.React.JavaScript] "Running application "UIExplorerApp" with appParams: {"rootTag":1,"initialProps":{}}. __DEV__ === true, development-level warning are ON, performance optimizations are OFF"
2015-05-06 15:45:05.881 [info][tid:com.facebook.React.JavaScript] "received text layout event
", {"target":27,"layout":{"y":123,"x":12.5,"width":140.5,"height":18}}
2015-05-06 15:45:05.882 [info][tid:com.facebook.React.JavaScript] "received image layout event
", {"target":23,"layout":{"y":12.5,"x":122,"width":50,"height":50}}
2015-05-06 15:45:05.883 [info][tid:com.facebook.React.JavaScript] "received view layout event
", {"target":22,"layout":{"y":70.5,"x":20,"width":294,"height":204}}
2015-05-06 15:45:05.897 [info][tid:com.facebook.React.JavaScript] "received text layout event
", {"target":27,"layout":{"y":206.5,"x":12.5,"width":140.5,"height":18}}
2015-05-06 15:45:05.897 [info][tid:com.facebook.React.JavaScript] "received view layout event
", {"target":22,"layout":{"y":70.5,"x":20,"width":294,"height":287.5}}
2015-05-06 15:45:09.847 [info][tid:com.facebook.React.JavaScript] "layout animation done."
2015-05-06 15:45:09.847 [info][tid:com.facebook.React.JavaScript] "received image layout event
", {"target":23,"layout":{"y":12.5,"x":82,"width":50,"height":50}}
2015-05-06 15:45:09.848 [info][tid:com.facebook.React.JavaScript] "received view layout event
", {"target":22,"layout":{"y":110.5,"x":60,"width":214,"height":287.5}}
2015-05-06 15:45:09.862 [info][tid:com.facebook.React.JavaScript] "received text layout event
", {"target":27,"layout":{"y":206.5,"x":12.5,"width":120,"height":68}}
2015-05-06 15:45:09.863 [info][tid:com.facebook.React.JavaScript] "received image layout event
", {"target":23,"layout":{"y":12.5,"x":55,"width":50,"height":50}}
2015-05-06 15:45:09.863 [info][tid:com.facebook.React.JavaScript] "received view layout event
", {"target":22,"layout":{"y":128,"x":60,"width":160,"height":337.5}}
```
Spencer Ahrens
Alexsander Akers
chaceliang
Nick Lockwood
Jakub Zika
Tadeu Zagallo