1 files changed, 107 insertions, 0 deletions
diff --git a/src/com/android/launcher3/views/SlidingTabStrip.java b/src/com/android/launcher3/views/SlidingTabStrip.java
new file mode 100644
index 000000000..45c626146
--- /dev/null
+++ b/src/com/android/launcher3/views/SlidingTabStrip.java
@@ -0,0 +1,107 @@
+/*
+ * 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.views;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.Button;
+import android.widget.LinearLayout;
+
+import com.android.launcher3.R;
+import com.android.launcher3.util.Themes;
+
+public class SlidingTabStrip extends LinearLayout {
+
+    private final Paint mSelectedIndicatorPaint;
+    private int mSelectedIndicatorHeight;
+    private int mIndicatorLeft = -1;
+    private int mIndicatorRight = -1;
+    private int mSelectedPosition = -1;
+    private float mSelectionOffset;
+
+    public SlidingTabStrip(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+        setOrientation(HORIZONTAL);
+        setWillNotDraw(false);
+        mSelectedIndicatorPaint = new Paint();
+        mSelectedIndicatorPaint.setColor(Themes.getAttrColor(context, android.R.attr.colorAccent));
+        mSelectedIndicatorHeight = getResources()
+                .getDimensionPixelSize(R.dimen.all_apps_tabs_indicator_height);
+    }
+
+    public void updateIndicatorPosition(int position, float positionOffset) {
+        mSelectedPosition = position;
+        mSelectionOffset = positionOffset;
+        updateIndicatorPosition();
+    }
+
+    public void updateTabTextColor(int pos) {
+        for (int i=0; i < getChildCount(); i++) {
+            Button tab = (Button) getChildAt(i);
+            tab.setSelected(i == pos);
+        }
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        super.onLayout(changed, l, t, r, b);
+        updateTabTextColor(0);
+        updateIndicatorPosition(0, 0);
+    }
+
+    private void updateIndicatorPosition() {
+        final View tab = getChildAt(mSelectedPosition);
+        int left, right;
+
+        if (tab != null && tab.getWidth() > 0) {
+            left = tab.getLeft();
+            right = tab.getRight();
+
+            if (mSelectionOffset > 0f && mSelectedPosition < getChildCount() - 1) {
+                // Draw the selection partway between the tabs
+                View nextTitle = getChildAt(mSelectedPosition + 1);
+                left = (int) (mSelectionOffset * nextTitle.getLeft() +
+                        (1.0f - mSelectionOffset) * left);
+                right = (int) (mSelectionOffset * nextTitle.getRight() +
+                        (1.0f - mSelectionOffset) * right);
+            }
+        } else {
+            left = right = -1;
+        }
+
+        setIndicatorPosition(left, right);
+    }
+
+    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);
+        canvas.drawRect(mIndicatorLeft, getHeight() - mSelectedIndicatorHeight,
+                mIndicatorRight, getHeight(), mSelectedIndicatorPaint);
+    }
+}
+\ No newline at end of file