Android9.0 修改状态栏图标之间的间距

操作

com.android.systemui.statusbar.phone/StatusBarIconController.java类中修改如下方法：

@VisibleForTesting
        protected StatusBarIconView addIcon(int index, String slot, boolean blocked,
                StatusBarIcon icon) {
            StatusBarIconView view = onCreateStatusBarIconView(slot, blocked);
            view.set(icon);
            //add:状态栏图标添加间距.
            view.setPadding(2,0,2,0);
            //end add.
            mGroup.addView(view, index, onCreateLayoutParams());
            return view;
        }

        @VisibleForTesting
        protected StatusBarWifiView addSignalIcon(int index, String slot, WifiIconState state) {
            StatusBarWifiView view = onCreateStatusBarWifiView(slot);
            view.applyWifiState(state);
            //add:状态栏图标添加间距.
            view.setPadding(2,0,2,0);
            //end add.
            mGroup.addView(view, index, onCreateLayoutParams());

            if (mIsInDemoMode) {
                mDemoStatusIcons.addDemoWifiView(state);
            }
            return view;
        }

        @VisibleForTesting
        protected StatusBarMobileView addMobileIcon(int index, String slot, MobileIconState state) {
            StatusBarMobileView view = onCreateStatusBarMobileView(slot);
            view.applyMobileState(state);
            //add:状态栏图标添加间距.
            view.setPadding(2,0,2,0);
            //end add.
            mGroup.addView(view, index, onCreateLayoutParams());

            if (mIsInDemoMode) {
                mDemoStatusIcons.addMobileView(state);
            }
            return view;
        }

原理

状态栏添加图标最终会调用到
com.android.systemui.statusbar.phone/StatusBarIconController.java类中的addHolder()方法：

protected StatusIconDisplayable addHolder(int index, String slot, boolean blocked,
                StatusBarIconHolder holder) {
            switch (holder.getType()) {
                case TYPE_ICON:
                    return addIcon(index, slot, blocked, holder.getIcon());

                case TYPE_WIFI:
                    return addSignalIcon(index, slot, holder.getWifiState());

                case TYPE_MOBILE:
                    return addMobileIcon(index, slot, holder.getMobileState());
            }

            return null;
        }

就是在这里将图标添加到@+id/statusIcons中的
布局文件status_bar.xml

...
<com.android.keyguard.AlphaOptimizedLinearLayout android:id="@+id/system_icon_area"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="3"
            android:orientation="horizontal"
            android:gravity="center_vertical|end"
            >

            <include layout="@layout/system_icons" />
        </com.android.keyguard.AlphaOptimizedLinearLayout>
...

system_icon.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/system_icons"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_vertical">

    <com.android.systemui.statusbar.phone.StatusIconContainer android:id="@+id/statusIcons"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="match_parent"
        android:paddingEnd="@dimen/signal_cluster_battery_padding"
        android:gravity="center_vertical"
        android:orientation="horizontal"/>

    <com.android.systemui.BatteryMeterView android:id="@+id/battery"
        android:layout_height="match_parent"
        android:layout_width="wrap_content"
        android:clipToPadding="false"
        android:clipChildren="false" />
</LinearLayout>

然后进入addIcon方法：

@VisibleForTesting
        protected StatusBarIconView addIcon(int index, String slot, boolean blocked,
                StatusBarIcon icon) {
            StatusBarIconView view = onCreateStatusBarIconView(slot, blocked);
            view.set(icon);
            mGroup.addView(view, index, onCreateLayoutParams());
            return view;
        }

addView的时候创建了onCreateLayoutParams()

public static class DarkIconManager extends IconManager {
       ...
        private int mIconHPadding;

        public DarkIconManager(LinearLayout linearLayout) {
            super(linearLayout);
            mIconHPadding = mContext.getResources().getDimensionPixelSize(
                    R.dimen.status_bar_icon_padding);
           ...
        }
        ...
        @Override
        protected LayoutParams onCreateLayoutParams() {
            LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
                    ViewGroup.LayoutParams.WRAP_CONTENT, mIconSize);
            lp.setMargins(mIconHPadding, 0, mIconHPadding, 0);
            return lp;
        }
}

这里可以设置一个margin,原生设置的0。

<!-- gap on either side of status bar notification icons -->
    <dimen name="status_bar_icon_padding">0dp</dimen>

注意坑在这里，不管这里的margin值设为多少，最后并不会生效，因为在StatusIconContainer.java类中onLayout()方法中并没有考虑这个margin

 @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        float midY = getHeight() / 2.0f;

        // Layout all child views so that we can move them around later
        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();
    }

既然添加margin不行，那就添加padding,如文章开头的代码所示。