1.概述
遇到需求，QuickQSPanel首次下拉后展示快捷功能模块以后就是显示QuickQSPanel，而不展开QSPanel，接下来要从下滑手势下拉出状态栏分析功能实现。也就是直接是展开状态。
2、涉及核心类
frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone
Android12或者Android13
frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone\NotificationPanelViewController.java
frameworks/base/packages/SystemUI/res/layout/status_bar_expanded.xml
Android10
frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone\NotificationPanelViewController.java
frameworks/base/packages/SystemUI/res/layout/status_bar_expanded.xml
3、SystemUI下拉状态栏禁止QuickQSPanel展开的核心功能分析和实现
在系统SystemUI中，它主要负责反馈系统及应用状态并与用户保持大量的交互,systemui中主要核心布局控件为以下部分
在SystemUI中，QSPanel 创建是从 StatusBar#makeStatusBarView 开始的
接下来分析的核心功能和布局如下:
StatusBar：通知消息提示和状态展现
NavigationBar：返回，HOME，Recent
KeyGuard：锁屏模块可以看做单独的应用，提供基本的手机个人隐私保护
Recents：近期应用管理，以堆叠栈的形式展现。
Notification Panel：展示系统或应用通知内容。提供快速系统设置开关。
VolumeUI：来用展示或控制音量的变化：媒体音量、铃声音量与闹钟音量
截屏界面：长按电源键+音量下键后截屏，用以展示截取的屏幕照片/内容
PowerUI：主要处理和Power相关的事件，比如省电模式切换、电池电量变化和开关屏事件等。
RingtonePlayer：铃声播放
StackDivider：控制管理分屏
PipUI：提供对于画中画模式的管理
3.1 status_bar_expanded.xml下拉状态栏布局分析
<?xml version="1.0" encoding="utf-8"?>
<!--
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->
<com.android.systemui.statusbar.phone.NotificationPanelView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:systemui="http://schemas.android.com/apk/res-auto"
android:id="@+id/notification_panel"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/transparent">
<FrameLayout
android:id="@+id/big_clock_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone" />
<ViewStub
android:id="@+id/keyguard_qs_user_switch_stub"
android:layout="@layout/keyguard_qs_user_switch"
android:layout_height="match_parent"
android:layout_width="match_parent" />
<include
layout="@layout/keyguard_bottom_area"
android:visibility="gone" />
<ViewStub
android:id="@+id/keyguard_user_switcher_stub"
android:layout="@layout/keyguard_user_switcher"
android:layout_height="match_parent"
android:layout_width="match_parent" />
<include layout="@layout/status_bar_expanded_plugin_frame"/>
<include layout="@layout/dock_info_bottom_area_overlay" />
<com.android.keyguard.LockIconView
android:id="@+id/lock_icon_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center">
<!-- Background protection -->
<ImageView
android:id="@+id/lock_icon_bg"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/fingerprint_bg"
android:visibility="invisible"/>
<ImageView
android:id="@+id/lock_icon"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="@dimen/lock_icon_padding"
android:layout_gravity="center"
android:scaleType="centerCrop"/>
</com.android.keyguard.LockIconView>
<com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="@integer/notification_panel_layout_gravity"
android:id="@+id/notification_container_parent"
android:clipToPadding="false"
android:clipChildren="false">
<include
layout="@layout/keyguard_status_view"
android:visibility="gone"/>
<include layout="@layout/dock_info_overlay" />
<FrameLayout
android:id="@+id/qs_frame"
android:layout="@layout/qs_panel"
android:layout_width="@dimen/qs_panel_width"
android:layout_height="0dp"
android:clipToPadding="false"
android:clipChildren="false"
systemui:viewType="com.android.systemui.plugins.qs.QS"
systemui:layout_constraintStart_toStartOf="parent"
systemui:layout_constraintEnd_toEndOf="parent"
systemui:layout_constraintTop_toTopOf="parent"
systemui:layout_constraintBottom_toBottomOf="parent"
/>
<androidx.constraintlayout.widget.Guideline
android:id="@+id/qs_edge_guideline"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
systemui:layout_constraintGuide_percent="0.5"
android:orientation="vertical"/>
<com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayout
android:id="@+id/notification_stack_scroller"
android:layout_marginTop="@dimen/notification_panel_margin_top"
android:layout_width="@dimen/notification_panel_width"
android:layout_height="match_parent"
android:layout_marginBottom="@dimen/close_handle_underlap"
systemui:layout_constraintStart_toStartOf="parent"
systemui:layout_constraintEnd_toEndOf="parent"
/>
<include layout="@layout/ambient_indication"
android:id="@+id/ambient_indication_container" />
<include layout="@layout/photo_preview_overlay" />
<include
layout="@layout/keyguard_status_bar"
android:visibility="invisible" />
<Button
android:id="@+id/report_rejected_touch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/status_bar_header_height_keyguard"
android:text="@string/report_rejected_touch"
android:visibility="gone" />
<com.android.systemui.statusbar.phone.TapAgainView
android:id="@+id/shade_falsing_tap_again"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
systemui:layout_constraintLeft_toLeftOf="parent"
systemui:layout_constraintRight_toRightOf="parent"
systemui:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="20dp"
android:paddingHorizontal="16dp"
android:minHeight="44dp"
android:elevation="4dp"
android:background="@drawable/rounded_bg_full"
android:gravity="center"
android:text="@string/tap_again"
android:visibility="gone"
/>
</com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer>
<FrameLayout
android:id="@+id/preview_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</com.android.systemui.statusbar.phone.NotificationPanelView>在实现SystemUI下拉状态栏禁止QuickQSPanel展开的核心功能中，通过上述的分析得知，
从SystemUI中状态栏下拉的布局status_bar_expanded.xml的布局文件可以看到主要的下拉事件
是在NotificationPanelViewController.java中负责的，所以具体的下滑事件是在NotificationPanelViewController.java中处理的
所以接下来分析NotificationPanelViewController.java有关下拉状态栏的下滑展开事件
3.2 NotificationPanelViewController.java的下拉状态栏下滑事件分析
NotificationPanelViewController是一个以面板形式展示通知内容的主要视图控制器。它可以显示系统通知，
例如来自操作系统的警告、提醒或更新通知，以及来自其他应用程序的通知，如社交媒体应用或
即时消息应用发送的消息通知。通过notificationPanelViewController，用户可以方便地查看和管理收到的通知。
public class NotificationPanelViewController extends PanelViewController { {
@Override
protected TouchHandler createTouchHandler() {
return new TouchHandler() {
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (mBlockTouches || mQsFullyExpanded && mQs.disallowPanelTouches()) {
return false;
}
initDownStates(event);
// Do not let touches go to shade or QS if the bouncer is visible,
// but still let user swipe down to expand the panel, dismissing the bouncer.
if (mStatusBar.isBouncerShowing()) {
return true;
}
if (mBar.panelEnabled() && mHeadsUpTouchHelper.onInterceptTouchEvent(event)) {
mMetricsLogger.count(COUNTER_PANEL_OPEN, 1);
mMetricsLogger.count(COUNTER_PANEL_OPEN_PEEK, 1);
return true;
}
if (!shouldQuickSettingsIntercept(mDownX, mDownY, 0)
&& mPulseExpansionHandler.onInterceptTouchEvent(event)) {
return true;
}
if (!isFullyCollapsed() && onQsIntercept(event)) {
return true;
}
return super.onInterceptTouchEvent(event);
}在实现SystemUI下拉状态栏禁止QuickQSPanel展开的核心功能中，通过上述的分析得知，
在NotificationPanelViewController中的onInterceptTouchEvent(MotionEvent event) 手势下滑上滑事件的
处理，而具体处理下拉状态栏下滑事件的是在onQsIntercept(MotionEvent event)中继续处理的
接下来看下onQsIntercept(MotionEvent event)处理手势事件
private boolean onQsIntercept(MotionEvent event) {
int pointerIndex = event.findPointerIndex(mTrackingPointer);
if (pointerIndex < 0) {
pointerIndex = 0;
mTrackingPointer = event.getPointerId(pointerIndex);
}
final float x = event.getX(pointerIndex);
final float y = event.getY(pointerIndex);
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
mIntercepting = true;
mInitialTouchY = y;
mInitialTouchX = x;
initVelocityTracker();
trackMovement(event);
if (shouldQuickSettingsIntercept(mInitialTouchX, mInitialTouchY, 0)) {
getParent().requestDisallowInterceptTouchEvent(true);
}
if (mQsExpansionAnimator != null) {
onQsExpansionStarted();
mInitialHeightOnTouch = mQsExpansionHeight;
mQsTracking = true;
mIntercepting = false;
mNotificationStackScroller.cancelLongPress();
}
break;
case MotionEvent.ACTION_POINTER_UP:
final int upPointer = event.getPointerId(event.getActionIndex());
if (mTrackingPointer == upPointer) {
// gesture is ongoing, find a new pointer to track
final int newIndex = event.getPointerId(0) != upPointer ? 0 : 1;
mTrackingPointer = event.getPointerId(newIndex);
mInitialTouchX = event.getX(newIndex);
mInitialTouchY = event.getY(newIndex);
}
break;
case MotionEvent.ACTION_MOVE:
final float h = y - mInitialTouchY;
trackMovement(event);
if (mQsTracking) {
// Already tracking because onOverscrolled was called. We need to update here
// so we don't stop for a frame until the next touch event gets handled in
// onTouchEvent.
setQsExpansion(h + mInitialHeightOnTouch);
trackMovement(event);
mIntercepting = false;
return true;
}
if (Math.abs(h) > mTouchSlop && Math.abs(h) > Math.abs(x - mInitialTouchX)
&& shouldQuickSettingsIntercept(mInitialTouchX, mInitialTouchY, h)) {
mQsTracking = true;
onQsExpansionStarted();
notifyExpandingFinished();
mInitialHeightOnTouch = mQsExpansionHeight;
mInitialTouchY = y;
mInitialTouchX = x;
mIntercepting = false;
mNotificationStackScroller.cancelLongPress();
return true;
}
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
trackMovement(event);
if (mQsTracking) {
flingQsWithCurrentVelocity(y,
event.getActionMasked() == MotionEvent.ACTION_CANCEL);
mQsTracking = false;
}
mIntercepting = false;
break;
}
return false;
}在实现SystemUI下拉状态栏禁止QuickQSPanel展开的核心功能中，通过上述的分析得知，
在NotificationPanelViewController中onQsIntercept(MotionEvent event)的是具体处理下拉事件的方法
在case MotionEvent.ACTION_MOVE:中可以根据手势滑动的距离来设置下拉状态栏中的
QSPanel展开和收缩，通过setQsExpansion(h + mInitialHeightOnTouch);来根据手势滑动的
距离来设置QSPanel是否需要展开，所以具体看下setQsExpansion的相关代码
private void setQsExpansion(float height) {
// add core start
if (mQs != null) return;
//add core end
height = Math.min(Math.max(height, mQsMinExpansionHeight), mQsMaxExpansionHeight);
mQsFullyExpanded = height == mQsMaxExpansionHeight && mQsMaxExpansionHeight != 0;
if (height > mQsMinExpansionHeight && !mQsExpanded && !mStackScrollerOverscrolling) {
setQsExpanded(true);
} else if (height <= mQsMinExpansionHeight && mQsExpanded) {
setQsExpanded(false);
}
mQsExpansionHeight = height;
updateQsExpansion();
requestScrollerTopPaddingUpdate(false /* animate */);
updateHeaderKeyguardAlpha();
if (mBarState == StatusBarState.SHADE_LOCKED
|| mBarState == StatusBarState.KEYGUARD) {
updateKeyguardBottomAreaAlpha();
updateBigClockAlpha();
}
if (mBarState == StatusBarState.SHADE && mQsExpanded
&& !mStackScrollerOverscrolling && mQsScrimEnabled) {
mQsNavbarScrim.setAlpha(getQsExpansionFraction());
}
if (mAccessibilityManager.isEnabled()) {
setAccessibilityPaneTitle(determineAccessibilityPaneTitle());
}
if (!mFalsingManager.isUnlockingDisabled() && mQsFullyExpanded
&& mFalsingManager.shouldEnforceBouncer()) {
mStatusBar.executeRunnableDismissingKeyguard(null, null /* cancelAction */,
false /* dismissShade */, true /* afterKeyguardGone */, false /* deferred */);
}
if (mExpansionListener != null) {
mExpansionListener.onQsExpansionChanged(mQsMaxExpansionHeight != 0
? mQsExpansionHeight / mQsMaxExpansionHeight : 0);
}
if (DEBUG) {
invalidate();
}
}4、修改
在实现SystemUI下拉状态栏禁止QuickQSPanel展开的核心功能中，通过上述的分析得知，
在NotificationPanelViewController.java类中setQsExpansion(float height) 方法来设置下拉状态栏
QSPanel高度的方法中，根据高度判断是否需要展开收缩QSPanel,所以通过增加判断
if (mQs != null)
return;来去掉下滑展开QSPanel，就可以做到只显示QuickQSPanel，而
不用展开QSPanel，实现单次下拉状态栏，定制UI 就可以在QuickQSPanel中定制就可以了
private void setQsExpansion(float height) {
// mQs 不等于空直接复用
if (mQs != null) return;
// mQs 等于空新建
height = Math.min(Math.max(height, mQsMinExpansionHeight), mQsMaxExpansionHeight);
mQsFullyExpanded = height == mQsMaxExpansionHeight && mQsMaxExpansionHeight != 0;
if (height > mQsMinExpansionHeight && !mQsExpanded && !mStackScrollerOverscrolling
&& !mDozing) {
setQsExpanded(true);
} else if (height <= mQsMinExpansionHeight && mQsExpanded) {
setQsExpanded(false);
}
mQsExpansionHeight = height;
updateQsExpansion();
requestScrollerTopPaddingUpdate(false /* animate */);
updateHeaderKeyguardAlpha();
if (mBarState == StatusBarState.SHADE_LOCKED || mBarState == KEYGUARD) {
updateKeyguardBottomAreaAlpha();
positionClockAndNotifications();
updateBigClockAlpha();
}
if (mAccessibilityManager.isEnabled()) {
mView.setAccessibilityPaneTitle(determineAccessibilityPaneTitle());
}
if (!mFalsingManager.isUnlockingDisabled() && mQsFullyExpanded
&& mFalsingCollector.shouldEnforceBouncer()) {
mStatusBar.executeRunnableDismissingKeyguard(null, null /* cancelAction */,
false /* dismissShade */, true /* afterKeyguardGone */, false /* deferred */);
}
for (int i = 0; i < mExpansionListeners.size(); i++) {
mExpansionListeners.get(i).onQsExpansionChanged(
mQsMaxExpansionHeight != 0 ? mQsExpansionHeight / mQsMaxExpansionHeight : 0);
}
if (DEBUG) {
mView.invalidate();
}
}