上一篇介绍了 DisplayContent 的基本概念和类源码 ：https://www.jianshu.com/p/8ad3ea741410
这里再仔细看看它所继承的父类和所实现的接口。
class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.DisplayContentInfo {
1. 直接父类 RootDisplayArea
从以下的源码可以看出，其与 IME 容器有较大关联，
例如 将 IME 容器放置在根目录下.
frameworks/base/services/core/java/com/android/server/wm/RootDisplayArea.java
package com.android.server.wm;
/**
* Root of a {@link DisplayArea} hierarchy. It can be either the {@link DisplayContent} as the root
* of the whole logical display, or a {@link DisplayAreaGroup} as the root of a partition of the
* logical display.
*/
class RootDisplayArea extends DisplayArea.Dimmable {
}
即 DisplayArea 层次结构的根.
它可以是 {@link DisplayContent} 作为整个逻辑显示的根,
或 {@link DisplayAreaGroup} 作为逻辑显示分区的根。
关键成员变量：
/** {@link Feature} that are supported in this {@link DisplayArea} hierarchy. */
List<DisplayAreaPolicyBuilder.Feature> mFeatures;
/**
* Mapping from policy supported {@link Feature} to list of {@link DisplayArea} created to cover
* all the window types that the {@link Feature} will be applied to.
*/
Map<Feature, List<DisplayArea<WindowContainer>>> mFeatureToDisplayAreas;
// 从窗口层 映射 到在该层上保存窗口的 DisplayArea.Tokens
/** Mapping from window layer to {@link DisplayArea.Tokens} that holds windows on that layer. */
private DisplayArea.Tokens[] mAreaForLayer;
/** Whether the hierarchy has been built. */
private boolean mHasBuiltHierarchy;
关键方法：
/**
* Places the IME container below this root, so that it's bounds and config will be updated to
* match the root. //将 IME 容器放置在此根目录下,这样它的边界和配置将被更新以匹配根
*/
void placeImeContainer(DisplayArea.Tokens imeContainer) {}
/**
* Finds the {@link DisplayArea.Tokens} in {@code mAreaForLayer} that this type of window
* should be attached to.
@Nullable
DisplayArea.Tokens findAreaForTokenInLayer(WindowToken token) {
/** Callback after {@link DisplayArea} hierarchy has been built. */
void onHierarchyBuilt(ArrayList<Feature> features, DisplayArea.Tokens[] areaForLayer,
Map<Feature, List<DisplayArea<WindowContainer>>> featureToDisplayAreas) {
private void updateImeContainerForLayers(@Nullable DisplayArea.Tokens imeContainer) {
final WindowManagerPolicy policy = mWmService.mPolicy;
mAreaForLayer[policy.getWindowLayerFromTypeLw(TYPE_INPUT_METHOD)] = imeContainer;
mAreaForLayer[policy.getWindowLayerFromTypeLw(TYPE_INPUT_METHOD_DIALOG)] = imeContainer;
}
2. 直接实现的接口 WindowManagerPolicy.DisplayContentInfo
即 获取 显示内容 的公共信息的接口.
frameworks/base/services/core/java/com/android/server/policy/WindowManagerPolicy.java
package com.android.server.policy;
public interface WindowManagerPolicy extends WindowManagerPolicyConstants {
/**
* Interface to get public information of a display content.
*/
public interface DisplayContentInfo {
DisplayRotation getDisplayRotation();
Display getDisplay();
}
999
基于 Android 14 源码. (20230912 codesearch main 分支)
