Android底层摸索改BUG（一）：Android系统状态栏显示不下Wifi图标

这是我入职的第一个BUG，头疼，隔壁实习生一周解决了，我多花了几天

其中最大的原因就是我思考复杂了，在公司系统上，此BUG标题为：

请确认Wifi优先级，状态栏Wifi被忽略

BUG意思就是：当前安卓系统状态栏图标有显示尺寸的测量，如果比如需要显示8个图标，已经在状态栏绘制不下，则显示一个点表示省略，而不希望wifi被省略

我思考了一下一直以为就是优先级问题，是不是Android底层状态栏有各个图标优先级，图标过多的时候优先级高的就不会被隐藏，而其实最后参考了公司以前相关BUG的修改，其实只是状态栏的图标大小修改即可，将图标改小，状态栏就可以多一个显示图标，Wifi就不会被隐藏。（点向后一个图标挪了一位）

在尺寸文件中进行修改：对这两个尺寸进行改小（可以调一下刷机看一下）

 <dimen name="status_bar_icon_size">14dip</dimen><dimen name="status_bar_system_icon_size">11.5dp</dimen>

值得一提的是上面的逻辑：超出的图标隐藏、绘制、测量相关的Java类是：StatusIconContainer.Java（虽然和BUG不在这改，记录一下）

/*** StatusIconContainer 是 StatusBarMobileView 内部的一个自定义视图容器，用于管理状态图标的显示。* 它负责在 StatusBarMobileView 中管理状态图标的布局和可见性。*/
public class StatusIconContainer extends AlphaOptimizedLinearLayout {//TAG    private static final String TAG = "StatusIconContainer";//是否打开DEBUG模式，会Log相关信息private static final boolean DEBUG = false;//是否打开DEBUG_OVERFLOW，会在状态栏绘制边框用来显示区域什么的private static final boolean DEBUG_OVERFLOW = false;// 最多可以显示 8 个状态图标，包括电池图标private static final int MAX_ICONS = 7;//    private static final int MAX_ICONS = 8;//点的个数        private static final int MAX_DOTS = 1;//Dot  点  Icon图标 相关属性private int mDotPadding;private int mIconSpacing;private int mStaticDotDiameter;private int mUnderflowWidth;private int mUnderflowStart = 0;// 是否可以在溢出空间中绘制private boolean mNeedsUnderflow;// 单个 StatusBarIconView 的点图标在此宽度内居中显示private int mIconDotFrameWidth;private boolean mShouldRestrictIcons = true;// 用于计算哪些状态要在布局期间可见private ArrayList<StatusIconState> mLayoutStates = new ArrayList<>();// 为了正确计数和测量private ArrayList<View> mMeasureViews = new ArrayList<>();// 任何被忽略的图标将不会被添加为子视图private ArrayList<String> mIgnoredSlots = new ArrayList<>();/*** 创建 StatusIconContainer 的构造函数。** @param context Android 上下文对象*/public StatusIconContainer(Context context) {this(context, null);}/*** 创建 StatusIconContainer 的构造函数。** @param context Android 上下文对象* @param attrs   属性集*/public StatusIconContainer(Context context, AttributeSet attrs) {super(context, attrs);initDimens();setWillNotDraw(!DEBUG_OVERFLOW);}@Overrideprotected void onFinishInflate() {super.onFinishInflate();}/*** 设置是否限制状态图标的显示。** @param should 是否应该限制状态图标的显示*/public void setShouldRestrictIcons(boolean should) {mShouldRestrictIcons = should;}/*** 检查是否正在限制状态图标的显示。** @return 如果正在限制状态图标的显示，则返回 true；否则返回 false。*/public boolean isRestrictingIcons() {return mShouldRestrictIcons;}/*** 初始化尺寸参数。*/private void initDimens() {// 这是与 StatusBarIconView 使用相同的值mIconDotFrameWidth = getResources().getDimensionPixelSize(com.android.internal.R.dimen.status_bar_icon_size);mDotPadding = getResources().getDimensionPixelSize(R.dimen.overflow_icon_dot_padding);mIconSpacing = getResources().getDimensionPixelSize(R.dimen.status_bar_system_icon_spacing);// 点图标int radius = getResources().getDimensionPixelSize(R.dimen.overflow_dot_radius);// 计算点的直径 R.dimen.overflow_dot_radius 2dpmStaticDotDiameter = 2 * radius;// 不能超过宽度 mIconDotFrameWidth 图标宽度 最大图标个数-1（可能还有个点，所以-1） 每个宽高mUnderflowWidth = mIconDotFrameWidth + (MAX_DOTS - 1) * (mStaticDotDiameter + mDotPadding);android.util.Log.d(TAG, "initDimens: " + mUnderflowStart);}@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {float midY = getHeight() / 2.0f;// 首先对所有子视图进行布局，以便稍后移动它们for (int i = 0; i < getChildCount(); i++) {View child = getChildAt(i);int width = child.getMeasuredWidth();int height = child.getMeasuredHeight();int top = (int) (midY - height / 2.0f);child.layout(0, top, width, top + height);}resetViewStates();calculateIconTranslations();applyIconStates();}
//绘制@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);if (DEBUG_OVERFLOW) {//如果开启了DEBUG_OVERFLOW模式画框框Paint paint = new Paint();paint.setStyle(Style.STROKE);paint.setColor(Color.RED);// 显示边界框canvas.drawRect(getPaddingStart(), 0, getWidth() - getPaddingEnd(), getHeight(), paint);// 显示溢出框paint.setColor(Color.GREEN);canvas.drawRect(mUnderflowStart, 0, mUnderflowStart + mUnderflowWidth, getHeight(), paint);}}//测量@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {mMeasureViews.clear();int mode = MeasureSpec.getMode(widthMeasureSpec);final int width = MeasureSpec.getSize(widthMeasureSpec);final int count = getChildCount();// 收集所有希望进行布局的视图for (int i = 0; i < count; i++) {// 获取子视图StatusIconDisplayable icon = (StatusIconDisplayable) getChildAt(i);// 如果视图可见且没有被阻止，则加入可见视图列表if (icon.isIconVisible() && !icon.isIconBlocked()&& !mIgnoredSlots.contains(icon.getSlot())) {mMeasureViews.add((View) icon);}}// 可见视图数量int visibleCount = mMeasureViews.size();int maxVisible = visibleCount <= MAX_ICONS ? MAX_ICONS : MAX_ICONS - 1;int totalWidth = mPaddingLeft + mPaddingRight;boolean trackWidth = true;// 测量所有子视图，以便它们报告正确的宽度int childWidthSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.UNSPECIFIED);mNeedsUnderflow = mShouldRestrictIcons && visibleCount > MAX_ICONS;for (int i = 0; i < visibleCount; i++) {View child = mMeasureViews.get(i);measureChild(child, childWidthSpec, heightMeasureSpec);int spacing = i == visibleCount - 1 ? 0 : mIconSpacing;if (mShouldRestrictIcons) {if (i < maxVisible && trackWidth) {totalWidth += getViewTotalMeasuredWidth(child) + spacing;} else if (trackWidth) {// 达到图标限制；为点图标添加空间totalWidth += mUnderflowWidth;trackWidth = false;}} else {totalWidth += getViewTotalMeasuredWidth(child) + spacing;}}if (mode == MeasureSpec.EXACTLY) {if (!mNeedsUnderflow && totalWidth > width) {mNeedsUnderflow = true;}setMeasuredDimension(width, MeasureSpec.getSize(heightMeasureSpec));} else {if (mode == MeasureSpec.AT_MOST && totalWidth > width) {mNeedsUnderflow = true;totalWidth = width;}setMeasuredDimension(totalWidth, MeasureSpec.getSize(heightMeasureSpec));}}@Overridepublic void onViewAdded(View child) {super.onViewAdded(child);StatusIconState vs = new StatusIconState();vs.justAdded = true;child.setTag(R.id.status_bar_view_state_tag, vs);}@Overridepublic void onViewRemoved(View child) {super.onViewRemoved(child);child.setTag(R.id.status_bar_view_state_tag, null);}/*** 添加要忽略的图标槽的名称。它将不会显示在布局中也不会被测量。** @param slotName 图标的名称，就像在 frameworks/base/core/res/res/values/config.xml 中定义的那样*/public void addIgnoredSlot(String slotName) {android.util.Log.d(TAG, "addIgnoredSlot: " + slotName);boolean added = addIgnoredSlotInternal(slotName);if (added) {requestLayout();}}/*** 添加要忽略的图标槽的名称的列表。** @param slots 要忽略的图标的名称列表*/public void addIgnoredSlots(List<String> slots) {for (String slot : slots) {android.util.Log.d(TAG, "addIgnoredSlots: " + slot);}boolean willAddAny = false;for (String slot : slots) {willAddAny |= addIgnoredSlotInternal(slot);}if (willAddAny) {requestLayout();}}/*** 内部添加要忽略的图标槽名称。** @param slotName 图标的名称，就像在 frameworks/base/core/res/res/values/config.xml 中定义的那样* @return 如果成功添加，则返回 true，否则返回 false*/private boolean addIgnoredSlotInternal(String slotName) {android.util.Log.d(TAG, "addIgnoredSlotInternal: " + slotName);if (mIgnoredSlots.contains(slotName)) {return false;}mIgnoredSlots.add(slotName);return true;}/*** 从忽略的图标槽中移除一个名称。** @param slotName 要移除的图标槽的名称*/public void removeIgnoredSlot(String slotName) {android.util.Log.d(TAG, "removeIgnoredSlot: " + slotName);boolean removed = mIgnoredSlots.remove(slotName);if (removed) {requestLayout();}}/*** 从忽略的图标槽中移除名称的列表。** @param slots 要移除的图标槽的名称列表*/public void removeIgnoredSlots(List<String> slots) {for (String slot: slots) {android.util.Log.d(TAG, "removeIgnoredSlot: " + slot);}boolean removedAny = false;for (String slot : slots) {removedAny |= mIgnoredSlots.remove(slot);}if (removedAny) {requestLayout();}}/*** 设置要忽略的图标槽的列表，清除当前的列表。** @param slots 要忽略的图标槽的名称列表*/public void setIgnoredSlots(List<String> slots) {mIgnoredSlots.clear();addIgnoredSlots(slots);}/*** 返回与特定槽名称相对应的视图。* 仅用于操作它如何呈现。** @param slot 槽名称，与 com.android.internal.R.config_statusBarIcons 中定义的名称相对应* @return 如果此容器拥有相应的视图，则返回该视图，否则返回 null*/public View getViewForSlot(String slot) {for (int i = 0; i < getChildCount(); i++) {View child = getChildAt(i);if (child instanceof StatusIconDisplayable&& ((StatusIconDisplayable) child).getSlot().equals(slot)) {return child;}}return null;}/*** 布局从右到左发生。*/private void calculateIconTranslations() {mLayoutStates.clear();float width = getWidth();float translationX = width - getPaddingEnd();float contentStart = getPaddingStart();int childCount = getChildCount();// Underflow === 不显示内容直到此索引if (DEBUG) Log.d(TAG, "calculateIconTranslations: start=" + translationX+ " width=" + width + " underflow=" + mNeedsUnderflow);// 收集所有希望可见的状态for (int i = childCount - 1; i >= 0; i--) {View child = getChildAt(i);StatusIconDisplayable iconView = (StatusIconDisplayable) child;StatusIconState childState = getViewStateFromChild(child);if (!iconView.isIconVisible() || iconView.isIconBlocked()|| mIgnoredSlots.contains(iconView.getSlot())) {childState.visibleState = STATE_HIDDEN;if (DEBUG) Log.d(TAG, "skipping child (" + iconView.getSlot() + ") not visible");continue;}// 移动 translationX 到布局的位置，以添加视图而不截断子视图translationX -= getViewTotalWidth(child);childState.visibleState = STATE_ICON;childState.xTranslation = translationX;mLayoutStates.add(0, childState);// 为下一个视图移动 translationX 以腾出间隔translationX -= mIconSpacing;}// 显示 1 至 MAX_ICONS 个图标，或 (MAX_ICONS - 1) 个图标 + 溢出int totalVisible = mLayoutStates.size();int maxVisible = totalVisible <= MAX_ICONS ? MAX_ICONS : MAX_ICONS - 1;mUnderflowStart = 0;int visible = 0;int firstUnderflowIndex = -1;for (int i = totalVisible - 1; i >= 0; i--) {StatusIconState state = mLayoutStates.get(i);// 如果在测量时发现需要溢出，则允许在此之前腾出空间if (mNeedsUnderflow && (state.xTranslation < (contentStart + mUnderflowWidth)) ||(mShouldRestrictIcons && visible >= maxVisible)) {firstUnderflowIndex = i;break;}mUnderflowStart = (int) Math.max(contentStart, state.xTranslation - mUnderflowWidth - mIconSpacing);visible++;}//开始判断是否超出  超出则画点if (firstUnderflowIndex != -1) {int totalDots = 0;int dotWidth = mStaticDotDiameter + mDotPadding;int dotOffset = mUnderflowStart + mUnderflowWidth - mIconDotFrameWidth;for (int i = firstUnderflowIndex; i >= 0; i--) {StatusIconState state = mLayoutStates.get(i);if (totalDots < MAX_DOTS) {state.xTranslation = dotOffset;state.visibleState = STATE_DOT;dotOffset -= dotWidth;totalDots++;} else {state.visibleState = STATE_HIDDEN;}}}// 从 NotificationIconContainer 中拿来的，不是最优解，但保持布局逻辑简洁if (isLayoutRtl()) {for (int i = 0; i < childCount; i++) {View child = getChildAt(i);StatusIconState state = getViewStateFromChild(child);state.xTranslation = width - state.xTranslation - child.getWidth();}}}private void applyIconStates() {for (int i = 0; i < getChildCount(); i++) {View child = getChildAt(i);StatusIconState vs = getViewStateFromChild(child);if (vs != null) {vs.applyToView(child);}}}private void resetViewStates() {for (int i = 0; i < getChildCount(); i++) {View child = getChildAt(i);StatusIconState vs = getViewStateFromChild(child);if (vs == null) {continue;}vs.initFrom(child);vs.alpha = 1.0f;vs.hidden = false;}}private static @Nullable StatusIconState getViewStateFromChild(View child) {return (StatusIconState) child.getTag(R.id.status_bar_view_state_tag);}private static int getViewTotalMeasuredWidth(View child) {return child.getMeasuredWidth() + child.getPaddingStart() + child.getPaddingEnd();}private static int getViewTotalWidth(View child) {return child.getWidth() + child.getPaddingStart() + child.getPaddingEnd();}public static class StatusIconState extends ViewState {/// StatusBarIconView.STATE_*public int visibleState = STATE_ICON;public boolean justAdded = true;// 从视图末尾的距离是最相关的，用于动画float distanceToViewEnd = -1;@Overridepublic void applyToView(View view) {float parentWidth = 0;if (view.getParent() instanceof View) {parentWidth = ((View) view.getParent()).getWidth();}float currentDistanceToEnd = parentWidth - xTranslation;if (!(view instanceof StatusIconDisplayable)) {return;}StatusIconDisplayable icon = (StatusIconDisplayable) view;AnimationProperties animationProperties = null;boolean animateVisibility = true;// 用于计算哪些状态在布局过程中是可见的，找出哪些属性的状态转换(如果有的话)我们需要动画// 确定要动画的状态转换的属性（如果有）if (justAdded|| icon.getVisibleState() == STATE_HIDDEN && visibleState == STATE_ICON) {// 图标正在出现，通过将其放在它将出现的位置并动画 alpha 来淡入它super.applyToView(view);view.setAlpha(0.f);icon.setVisibleState(STATE_HIDDEN);animationProperties = ADD_ICON_PROPERTIES;} else if (icon.getVisibleState() != visibleState) {if (icon.getVisibleState() == STATE_ICON && visibleState == STATE_HIDDEN) {// 消失，不要执行任何复杂的操作animateVisibility = false;} else {// 所有其他转换（到/从点等）animationProperties = ANIMATE_ALL_PROPERTIES;}} else if (visibleState != STATE_HIDDEN && distanceToViewEnd != currentDistanceToEnd) {// 可见性不在发生变化，只需动画位置animationProperties = X_ANIMATION_PROPERTIES;}icon.setVisibleState(visibleState, animateVisibility);if (animationProperties != null) {view.animate().cancel();icon.addTransformationToViewGroup(view, animationProperties, null);}icon.applyInShelfTransformation(view, this, animationProperties, animationProperties);}}
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