1 files changed, 109 insertions, 0 deletions
diff --git a/java/com/android/contacts/common/list/ViewPagerTabStrip.java b/java/com/android/contacts/common/list/ViewPagerTabStrip.java
new file mode 100644
index 000000000..969a6d342
--- /dev/null
+++ b/java/com/android/contacts/common/list/ViewPagerTabStrip.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2014 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.contacts.common.list;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.LinearLayout;
+import com.android.contacts.common.R;
+
+public class ViewPagerTabStrip extends LinearLayout {
+
+  private final Paint mSelectedUnderlinePaint;
+  private int mSelectedUnderlineThickness;
+  private int mIndexForSelection;
+  private float mSelectionOffset;
+
+  public ViewPagerTabStrip(Context context) {
+    this(context, null);
+  }
+
+  public ViewPagerTabStrip(Context context, AttributeSet attrs) {
+    super(context, attrs);
+
+    final Resources res = context.getResources();
+
+    mSelectedUnderlineThickness = res.getDimensionPixelSize(R.dimen.tab_selected_underline_height);
+    int underlineColor = res.getColor(R.color.tab_selected_underline_color);
+    int backgroundColor = res.getColor(R.color.contactscommon_actionbar_background_color);
+
+    mSelectedUnderlinePaint = new Paint();
+    mSelectedUnderlinePaint.setColor(underlineColor);
+
+    setBackgroundColor(backgroundColor);
+    setWillNotDraw(false);
+  }
+
+  /**
+   * Notifies this view that view pager has been scrolled. We save the tab index and selection
+   * offset for interpolating the position and width of selection underline.
+   */
+  void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+    mIndexForSelection = position;
+    mSelectionOffset = positionOffset;
+    invalidate();
+  }
+
+  @Override
+  protected void onDraw(Canvas canvas) {
+    int childCount = getChildCount();
+
+    // Thick colored underline below the current selection
+    if (childCount > 0) {
+      View selectedTitle = getChildAt(mIndexForSelection);
+
+      if (selectedTitle == null) {
+        // The view pager's tab count changed but we weren't notified yet. Ignore this draw
+        // pass, when we get a new selection we will update and draw the selection strip in
+        // the correct place.
+        return;
+      }
+      int selectedLeft = selectedTitle.getLeft();
+      int selectedRight = selectedTitle.getRight();
+      final boolean isRtl = isRtl();
+      final boolean hasNextTab =
+          isRtl ? mIndexForSelection > 0 : (mIndexForSelection < (getChildCount() - 1));
+      if ((mSelectionOffset > 0.0f) && hasNextTab) {
+        // Draw the selection partway between the tabs
+        View nextTitle = getChildAt(mIndexForSelection + (isRtl ? -1 : 1));
+        int nextLeft = nextTitle.getLeft();
+        int nextRight = nextTitle.getRight();
+
+        selectedLeft =
+            (int) (mSelectionOffset * nextLeft + (1.0f - mSelectionOffset) * selectedLeft);
+        selectedRight =
+            (int) (mSelectionOffset * nextRight + (1.0f - mSelectionOffset) * selectedRight);
+      }
+
+      int height = getHeight();
+      canvas.drawRect(
+          selectedLeft,
+          height - mSelectedUnderlineThickness,
+          selectedRight,
+          height,
+          mSelectedUnderlinePaint);
+    }
+  }
+
+  private boolean isRtl() {
+    return getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
+  }
+}