aosp安卓15新特性dump的wms窗口层级树优化的更加美观

背景：

近来在体验调试aosp15时候，使用了dumpsys activity containers时候，发现wms层级结构树有一个巨大的变化。
很多学员朋友对这个优化改进都给出巨大的点赞，有的学员朋友还想老版本自己实现一下这种树绘制：

对比安卓14老版本情况

明显可以看出以前的wms层级结构树看着不像一颗树，靠的序号和空格在区分，但是层级一多，而且相差不多时候，如果只相差一层空格就不明显了，经常可能需要对半天才对的清楚。

aosp15和老版本的源码分析对比：

aosp15代码

/**
     * Dumps the names of this container children in the input print writer indenting each
     * level with the input prefix.
     */
    public void dumpChildrenNames(PrintWriter pw, String prefix, boolean isLastChild) {
        int curWinMode = getWindowingMode();
        String winMode = windowingModeToString(curWinMode);
        if (curWinMode != WINDOWING_MODE_UNDEFINED &&
                curWinMode != WINDOWING_MODE_FULLSCREEN) {
            winMode = winMode.toUpperCase();
        }
        int requestedWinMode = getRequestedOverrideWindowingMode();
        String overrideWinMode = windowingModeToString(requestedWinMode);
        if (requestedWinMode != WINDOWING_MODE_UNDEFINED &&
                requestedWinMode != WINDOWING_MODE_FULLSCREEN) {
            overrideWinMode = overrideWinMode.toUpperCase();
        }
        String actType = activityTypeToString(getActivityType());
        if (getActivityType() != ACTIVITY_TYPE_UNDEFINED
                && getActivityType() != ACTIVITY_TYPE_STANDARD) {
            actType = actType.toUpperCase();
        }
        pw.print(prefix + (isLastChild ? "└─ " : "├─ "));//isLastChild属于新参数，绘制树枝的看看是不是最后一个child
        pw.println(getName()
                + " type=" + actType
                + " mode=" + winMode
                + " override-mode=" + overrideWinMode
                + " requested-bounds=" + getRequestedOverrideBounds().toShortString()
                + " bounds=" + getBounds().toShortString());

        String childPrefix = prefix + (isLastChild ? "   " : "│  ");//注意这个是给子节点的标签，要么是空格要么是竖线
        for (int i = getChildCount() - 1; i >= 0; --i) {
            final E cc = getChildAt(i);
            cc.dumpChildrenNames(pw, childPrefix, i == 0 /* isLastChild */);
        }
    }

aosp14代码

      /**
     * Dumps the names of this container children in the input print writer indenting each
     * level with the input prefix.
     */
    public void dumpChildrenNames(PrintWriter pw, String prefix) {
        final String childPrefix = prefix + " ";//这里有给每一层增加空格
        pw.println(getName()
                + " type=" + activityTypeToString(getActivityType())
                + " mode=" + windowingModeToString(getWindowingMode())
                + " override-mode=" + windowingModeToString(getRequestedOverrideWindowingMode())
                + " requested-bounds=" + getRequestedOverrideBounds().toShortString()
                + " bounds=" + getBounds().toShortString());
        for (int i = getChildCount() - 1; i >= 0; --i) {
            final E cc = getChildAt(i);
            pw.print(childPrefix + "#" + i + " ");//这里主要表示child的索引
            cc.dumpChildrenNames(pw, childPrefix);
        }
    }

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