Extract common codes for personal / work profile tabs

These codes can be reused in the FullWidgetsSheet which we will be
adding tabs for personal / work profile.

Test: Set up work profile and then switch person / work profile tabs
      in the AllAppsContainerView.

Bug: 179797520

Change-Id: Ib7eb1190e1384a664cbe3e34411c9362f1f6db03

src/com/android/launcher3/workprofile/PersonalWorkSlidingTabStrip.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+package com.android.launcher3.workprofile;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.Button;
+import android.widget.LinearLayout;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.android.launcher3.R;
+import com.android.launcher3.Utilities;
+import com.android.launcher3.pageindicators.PageIndicator;
+import com.android.launcher3.util.Themes;
+
+/**
+ * Supports two indicator colors, dedicated for personal and work tabs.
+ */
+public class PersonalWorkSlidingTabStrip extends LinearLayout implements PageIndicator {
+    private final Paint mSelectedIndicatorPaint;
+    private final Paint mDividerPaint;
+
+    private int mSelectedIndicatorHeight;
+    private int mIndicatorLeft = -1;
+    private int mIndicatorRight = -1;
+    private float mScrollOffset;
+    private int mSelectedPosition = 0;
+
+    private OnActivePageChangedListener mOnActivePageChangedListener;
+    private int mLastActivePage = 0;
+    private boolean mIsRtl;
+
+    public PersonalWorkSlidingTabStrip(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+        setOrientation(HORIZONTAL);
+        setWillNotDraw(false);
+
+        mSelectedIndicatorHeight =
+                getResources().getDimensionPixelSize(R.dimen.all_apps_tabs_indicator_height);
+
+        mSelectedIndicatorPaint = new Paint();
+        mSelectedIndicatorPaint.setColor(
+                Themes.getAttrColor(context, android.R.attr.colorAccent));
+
+        mDividerPaint = new Paint();
+        mDividerPaint.setColor(Themes.getAttrColor(context, android.R.attr.colorControlHighlight));
+        mDividerPaint.setStrokeWidth(
+                getResources().getDimensionPixelSize(R.dimen.all_apps_divider_height));
+
+        mIsRtl = Utilities.isRtl(getResources());
+    }
+
+    /**
+     * Highlights tab with index pos
+     */
+    public void updateTabTextColor(int pos) {
+        mSelectedPosition = pos;
+        for (int i = 0; i < getChildCount(); i++) {
+            Button tab = (Button) getChildAt(i);
+            tab.setSelected(i == pos);
+        }
+    }
+
+    private void updateIndicatorPosition(float scrollOffset) {
+        mScrollOffset = scrollOffset;
+        updateIndicatorPosition();
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        super.onLayout(changed, l, t, r, b);
+        updateTabTextColor(mSelectedPosition);
+        updateIndicatorPosition(mScrollOffset);
+    }
+
+    private void updateIndicatorPosition() {
+        int left = -1, right = -1;
+        final View leftTab = getLeftTab();
+        if (leftTab != null) {
+            left = (int) (leftTab.getLeft() + leftTab.getWidth() * mScrollOffset);
+            right = left + leftTab.getWidth();
+        }
+        setIndicatorPosition(left, right);
+    }
+
+    private View getLeftTab() {
+        return mIsRtl ? getChildAt(1) : getChildAt(0);
+    }
+
+    private void setIndicatorPosition(int left, int right) {
+        if (left != mIndicatorLeft || right != mIndicatorRight) {
+            mIndicatorLeft = left;
+            mIndicatorRight = right;
+            invalidate();
+        }
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+
+        float y = getHeight() - mDividerPaint.getStrokeWidth();
+        canvas.drawLine(getPaddingLeft(), y, getWidth() - getPaddingRight(), y, mDividerPaint);
+        canvas.drawRect(mIndicatorLeft, getHeight() - mSelectedIndicatorHeight,
+                mIndicatorRight, getHeight(), mSelectedIndicatorPaint);
+    }
+
+    @Override
+    public void setScroll(int currentScroll, int totalScroll) {
+        float scrollOffset = ((float) currentScroll) / totalScroll;
+        updateIndicatorPosition(scrollOffset);
+    }
+
+    @Override
+    public void setActiveMarker(int activePage) {
+        updateTabTextColor(activePage);
+        if (mOnActivePageChangedListener != null && mLastActivePage != activePage) {
+            updateIndicatorPosition(activePage);
+            mOnActivePageChangedListener.onActivePageChanged(activePage);
+        }
+        mLastActivePage = activePage;
+    }
+
+    public void setOnActivePageChangedListener(OnActivePageChangedListener listener) {
+        mOnActivePageChangedListener = listener;
+    }
+
+    @Override
+    public void setMarkersCount(int numMarkers) { }
+
+    @Override
+    public boolean hasOverlappingRendering() {
+        return false;
+    }
+
+    /**
+     * Interface definition for a callback to be invoked when an active page has been changed.
+     */
+    public interface OnActivePageChangedListener {
+        /** Called when the active page has been changed. */
+        void onActivePageChanged(int currentActivePage);
+    }
+}