Move custom ViewPagerTabs into common

Bug: 16158921
Bug: 15616182
Change-Id: I164fe830636577f85357aa3bf1ddf803de9abf94
diff --git a/src/com/android/contacts/common/list/ViewPagerTabStrip.java b/src/com/android/contacts/common/list/ViewPagerTabStrip.java
new file mode 100644
index 0000000..f8a0040
--- /dev/null
+++ b/src/com/android/contacts/common/list/ViewPagerTabStrip.java
@@ -0,0 +1,105 @@
+/*
+ * 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 int mSelectedUnderlineThickness;
+    private final Paint mSelectedUnderlinePaint;
+
+    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.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();
+    }
+
+    /**
+     * Notifies this view that a new page has been selected in the view pager. We save the tab
+     * index and reset the selection offset to 0.
+     */
+    void onPageSelected(int position) {
+        mIndexForSelection = position;
+        mSelectionOffset = 0;
+        invalidate();
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        int childCount = getChildCount();
+
+        // Thick colored underline below the current selection
+        if (childCount > 0) {
+            View selectedTitle = getChildAt(mIndexForSelection);
+            int selectedLeft = selectedTitle.getLeft();
+            int selectedRight = selectedTitle.getRight();
+            if ((mSelectionOffset > 0.0f) &&
+                    (mIndexForSelection < (getChildCount() - 1))) {
+                // Draw the selection partway between the tabs
+                View nextTitle = getChildAt(mIndexForSelection + 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);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/contacts/common/list/ViewPagerTabs.java b/src/com/android/contacts/common/list/ViewPagerTabs.java
new file mode 100644
index 0000000..0bed717
--- /dev/null
+++ b/src/com/android/contacts/common/list/ViewPagerTabs.java
@@ -0,0 +1,216 @@
+/*
+ * 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.ColorStateList;
+import android.content.res.TypedArray;
+import android.graphics.Outline;
+import android.support.v4.view.PagerAdapter;
+import android.support.v4.view.ViewPager;
+import android.util.AttributeSet;
+import android.util.TypedValue;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewOutlineProvider;
+import android.widget.FrameLayout;
+import android.widget.HorizontalScrollView;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import com.android.contacts.common.R;
+
+/**
+ * Lightweight implementation of ViewPager tabs. This looks similar to traditional actionBar tabs,
+ * but allows for the view containing the tabs to be placed anywhere on screen. Text-related
+ * attributes can also be assigned in XML - these will get propogated to the child TextViews
+ * automatically.
+ */
+public class ViewPagerTabs extends HorizontalScrollView implements ViewPager.OnPageChangeListener {
+
+    ViewPager mPager;
+    private ViewPagerTabStrip mTabStrip;
+
+    /**
+     * Linearlayout that will contain the TextViews serving as tabs. This is the only child
+     * of the parent HorizontalScrollView.
+     */
+    final int mTextStyle;
+    final ColorStateList mTextColor;
+    final int mTextSize;
+    final boolean mTextAllCaps;
+    int mPrevSelected = -1;
+    int mSidePadding;
+
+    private static final ViewOutlineProvider VIEW_BOUNDS_OUTLINE_PROVIDER =
+            new ViewOutlineProvider() {
+        @Override
+        public void getOutline(View view, Outline outline) {
+            outline.setRect(0, 0, view.getWidth(), view.getHeight());
+        }
+    };
+
+    private static final int TAB_SIDE_PADDING_IN_DPS = 10;
+
+    // TODO: This should use <declare-styleable> in the future
+    private static final int[] ATTRS = new int[] {
+        android.R.attr.textSize,
+        android.R.attr.textStyle,
+        android.R.attr.textColor,
+        android.R.attr.textAllCaps
+    };
+
+    /**
+     * Simulates actionbar tab behavior by showing a toast with the tab title when long clicked.
+     */
+    private class OnTabLongClickListener implements OnLongClickListener {
+        final int mPosition;
+
+        public OnTabLongClickListener(int position) {
+            mPosition = position;
+        }
+
+        @Override
+        public boolean onLongClick(View v) {
+            final int[] screenPos = new int[2];
+            getLocationOnScreen(screenPos);
+
+            final Context context = getContext();
+            final int width = getWidth();
+            final int height = getHeight();
+            final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
+
+            Toast toast = Toast.makeText(context, mPager.getAdapter().getPageTitle(mPosition),
+                    Toast.LENGTH_SHORT);
+
+            // Show the toast under the tab
+            toast.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL,
+                    (screenPos[0] + width / 2) - screenWidth / 2, screenPos[1] + height);
+
+            toast.show();
+            return true;
+        }
+    }
+
+    public ViewPagerTabs(Context context) {
+        this(context, null);
+    }
+
+    public ViewPagerTabs(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public ViewPagerTabs(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        setFillViewport(true);
+
+        mSidePadding = (int) (getResources().getDisplayMetrics().density * TAB_SIDE_PADDING_IN_DPS);
+
+        final TypedArray a = context.obtainStyledAttributes(attrs, ATTRS);
+        mTextSize = a.getDimensionPixelSize(0, 0);
+        mTextStyle = a.getInt(1, 0);
+        mTextColor = a.getColorStateList(2);
+        mTextAllCaps = a.getBoolean(3, false);
+
+        mTabStrip = new ViewPagerTabStrip(context);
+        addView(mTabStrip,
+                new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT));
+        a.recycle();
+
+        // enable shadow casting from view bounds
+        setOutlineProvider(VIEW_BOUNDS_OUTLINE_PROVIDER);
+    }
+
+    public void setViewPager(ViewPager viewPager) {
+        mPager = viewPager;
+        addTabs(mPager.getAdapter());
+    }
+
+    private void addTabs(PagerAdapter adapter) {
+        mTabStrip.removeAllViews();
+
+        final int count = adapter.getCount();
+        for (int i = 0; i < count; i++) {
+            addTab(adapter.getPageTitle(i), i);
+        }
+    }
+
+    private void addTab(CharSequence tabTitle, final int position) {
+        final TextView textView = new TextView(getContext());
+        textView.setText(tabTitle);
+        textView.setBackgroundResource(R.drawable.view_pager_tab_background);
+        textView.setGravity(Gravity.CENTER);
+        textView.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mPager.setCurrentItem(position);
+            }
+        });
+
+        textView.setOnLongClickListener(new OnTabLongClickListener(position));
+
+        // Assign various text appearance related attributes to child views.
+        if (mTextStyle > 0) {
+            textView.setTypeface(textView.getTypeface(), mTextStyle);
+        }
+        if (mTextSize > 0) {
+            textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
+        }
+        if (mTextColor != null) {
+            textView.setTextColor(mTextColor);
+        }
+        textView.setAllCaps(mTextAllCaps);
+        textView.setPadding(mSidePadding, 0, mSidePadding, 0);
+        mTabStrip.addView(textView, new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
+                LayoutParams.MATCH_PARENT, 1));
+        // Default to the first child being selected
+        if (position == 0) {
+            mPrevSelected = 0;
+            textView.setSelected(true);
+        }
+    }
+
+    @Override
+    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+        int tabStripChildCount = mTabStrip.getChildCount();
+        if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
+            return;
+        }
+
+        mTabStrip.onPageScrolled(position, positionOffset, positionOffsetPixels);
+        smoothScrollTo(position, 0);
+    }
+
+    @Override
+    public void onPageSelected(int position) {
+        if (mPrevSelected >= 0) {
+            mTabStrip.getChildAt(mPrevSelected).setSelected(false);
+        }
+        final View selectedChild = mTabStrip.getChildAt(position);
+        selectedChild.setSelected(true);
+
+        // Update scroll position
+        final int scrollPos = selectedChild.getLeft() - (getWidth() - selectedChild.getWidth()) / 2;
+        smoothScrollTo(scrollPos, 0);
+        mPrevSelected = position;
+    }
+
+    @Override
+    public void onPageScrollStateChanged(int state) {
+    }
+}
+