Android Input系统之 InputMonitor 更新流程

最新推荐文章于 2024-06-05 01:01:05 发布

Big Skipper

最新推荐文章于 2024-06-05 01:01:05 发布

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分类专栏： Android framework 文章标签： android

本文链接：https://blog.youkuaiyun.com/liuwg1226/article/details/135936128

分析源码为 android 12

一、InputMonitor层面分析

在 WMS 添加，更新和删除Window 的时候都会调用 InputMonitor 的 updateInputWindowsLw 更新 window 信息。如下是删除window 时候的调用函数：

WMS.java

void removeWindowToken(IBinder binder, boolean removeWindows, boolean animateExit,
            int displayId) {
   
   
        synchronized (mGlobalLock) {
   
   
            final DisplayContent dc = mRoot.getDisplayContent(displayId);

            if (dc == null) {
   
   
                ProtoLog.w(WM_ERROR, "removeWindowToken: Attempted to remove token: %s"
                        + " for non-exiting displayId=%d", binder, displayId);
                return;
            }
            final WindowToken token = dc.removeWindowToken(binder, animateExit);
            if (token == null) {
   
   
                ProtoLog.w(WM_ERROR,
                        "removeWindowToken: Attempted to remove non-existing token: %s",
                        binder);
                return;
            }

            if (removeWindows) {
   
   
                token.removeAllWindowsIfPossible();
            }
            // 调用 updateInputWindowsLw
            dc.getInputMonitor().updateInputWindowsLw(true /* force */);
        }
    }

updateInputWindowsLw 属于经常被外部调用的方法，它会最后触发到UpdateInputWindows 的 run 方法执行。

private class UpdateInputWindows implements Runnable {
   
   
        @Override
        public void run() {
   
   
            synchronized (mService.mGlobalLock) {
   
   
                mUpdateInputWindowsPending = false;
                mUpdateInputWindowsNeeded = false;

                if (mDisplayRemoved) {
   
   
                    return;
                }

                // Populate the input window list with information about all of the windows that
                // could potentially receive input.
                // As an optimization, we could try to prune the list of windows but this turns
                // out to be difficult because only the native code knows for sure which window
                // currently has touch focus.

                // If there's a drag in flight, provide a pseudo-window to catch drag input
                final boolean inDrag = mService.mDragDropController.dragDropActiveLocked();

                // Add all windows on the default display.
                mUpdateInputForAllWindowsConsumer.updateInputWindows(inDrag);
            }
        }
    }

最后会调用到mUpdateInputForAllWindowsConsumer.updateInputWindows(inDrag);这个关键方法：

private final class UpdateInputForAllWindowsConsumer implements Consumer<WindowState> {
   
   
        InputConsumerImpl mPipInputConsumer;
        InputConsumerImpl mWallpaperInputConsumer;
        InputConsumerImpl mRecentsAnimationInputConsumer;

        private boolean mAddPipInputConsumerHandle;
        private boolean mAddWallpaperInputConsumerHandle;
        private boolean mAddRecentsAnimationInputConsumerHandle;

        boolean mInDrag;

        private void updateInputWindows(boolean inDrag) {
   
   
            Trace.traceBegin(TRACE_TAG_WINDOW_MANAGER, "updateInputWindows");

            ......
            mDisplayContent.forAllWindows(this, true /* traverseTopToBottom */);
            updateInputFocusRequest(mRecentsAnimationInputConsumer);

            ......
            }

            Trace.traceEnd(TRACE_TAG_WINDOW_MANAGER);
        }

.