Merge "SlidingTabLayout common component" into klp-dev
diff --git a/common/src/java/com/example/android/common/view/SlidingTabLayout.java b/common/src/java/com/example/android/common/view/SlidingTabLayout.java
new file mode 100644
index 0000000..20049e3
--- /dev/null
+++ b/common/src/java/com/example/android/common/view/SlidingTabLayout.java
@@ -0,0 +1,314 @@
+/*
+ * Copyright (C) 2013 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.example.android.common.view;
+
+import android.content.Context;
+import android.graphics.Typeface;
+import android.os.Build;
+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.LayoutInflater;
+import android.view.View;
+import android.widget.HorizontalScrollView;
+import android.widget.TextView;
+
+/**
+ * To be used with ViewPager to provide a tab indicator component which give constant feedback as to
+ * the user's scroll progress.
+ * <p>
+ * To use the component, simply add it to your view hierarchy. Then in your
+ * {@link android.app.Activity} or {@link android.support.v4.app.Fragment} call
+ * {@link #setViewPager(ViewPager)} providing it the ViewPager this layout is being used for.
+ * <p>
+ * The colors can be customized in two ways. The first and simplest is to provide an array of colors
+ * via {@link #setSelectedIndicatorColors(int...)} and {@link #setDividerColors(int...)}. The
+ * alternative is via the {@link TabColorizer} interface which provides you complete control over
+ * which color is used for any individual position.
+ * <p>
+ * The views used as tabs can be customized by calling {@link #setCustomTabView(int, int)},
+ * providing the layout ID of your custom layout.
+ */
+public class SlidingTabLayout extends HorizontalScrollView {
+
+ /**
+ * Allows complete control over the colors drawn in the tab layout. Set with
+ * {@link #setCustomTabColorizer(TabColorizer)}.
+ */
+ public interface TabColorizer {
+
+ /**
+ * @return return the color of the indicator used when {@code position} is selected.
+ */
+ int getIndicatorColor(int position);
+
+ /**
+ * @return return the color of the divider drawn to the right of {@code position}.
+ */
+ int getDividerColor(int position);
+
+ }
+
+ private static final int TITLE_OFFSET_DIPS = 24;
+ private static final int TAB_VIEW_PADDING_DIPS = 16;
+ private static final int TAB_VIEW_TEXT_SIZE_SP = 12;
+
+ private int mTitleOffset;
+
+ private int mTabViewLayoutId;
+ private int mTabViewTextViewId;
+
+ private ViewPager mViewPager;
+ private ViewPager.OnPageChangeListener mViewPagerPageChangeListener;
+
+ private final SlidingTabStrip mTabStrip;
+
+ public SlidingTabLayout(Context context) {
+ this(context, null);
+ }
+
+ public SlidingTabLayout(Context context, AttributeSet attrs) {
+ this(context, attrs, 0);
+ }
+
+ public SlidingTabLayout(Context context, AttributeSet attrs, int defStyle) {
+ super(context, attrs, defStyle);
+
+ // Disable the Scroll Bar
+ setHorizontalScrollBarEnabled(false);
+ // Make sure that the Tab Strips fills this View
+ setFillViewport(true);
+
+ mTitleOffset = (int) (TITLE_OFFSET_DIPS * getResources().getDisplayMetrics().density);
+
+ mTabStrip = new SlidingTabStrip(context);
+ addView(mTabStrip, LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
+ }
+
+ /**
+ * Set the custom {@link TabColorizer} to be used.
+ *
+ * If you only require simple custmisation then you can use
+ * {@link #setSelectedIndicatorColors(int...)} and {@link #setDividerColors(int...)} to achieve
+ * similar effects.
+ */
+ public void setCustomTabColorizer(TabColorizer tabColorizer) {
+ mTabStrip.setCustomTabColorizer(tabColorizer);
+ }
+
+ /**
+ * Sets the colors to be used for indicating the selected tab. These colors are treated as a
+ * circular array. Providing one color will mean that all tabs are indicated with the same color.
+ */
+ public void setSelectedIndicatorColors(int... colors) {
+ mTabStrip.setSelectedIndicatorColors(colors);
+ }
+
+ /**
+ * Sets the colors to be used for tab dividers. These colors are treated as a circular array.
+ * Providing one color will mean that all tabs are indicated with the same color.
+ */
+ public void setDividerColors(int... colors) {
+ mTabStrip.setDividerColors(colors);
+ }
+
+ /**
+ * Set the {@link ViewPager.OnPageChangeListener}. When using {@link SlidingTabLayout} you are
+ * required to set any {@link ViewPager.OnPageChangeListener} through this method. This is so
+ * that the layout can update it's scroll position correctly.
+ *
+ * @see ViewPager#setOnPageChangeListener(ViewPager.OnPageChangeListener)
+ */
+ public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
+ mViewPagerPageChangeListener = listener;
+ }
+
+ /**
+ * Set the custom layout to be inflated for the tab views.
+ *
+ * @param layoutResId Layout id to be inflated
+ * @param textViewId id of the {@link TextView} in the inflated view
+ */
+ public void setCustomTabView(int layoutResId, int textViewId) {
+ mTabViewLayoutId = layoutResId;
+ mTabViewTextViewId = textViewId;
+ }
+
+ /**
+ * Sets the associated view pager. Note that the assumption here is that the pager content
+ * (number of tabs and tab titles) does not change after this call has been made.
+ */
+ public void setViewPager(ViewPager viewPager) {
+ mTabStrip.removeAllViews();
+
+ mViewPager = viewPager;
+ if (viewPager != null) {
+ viewPager.setOnPageChangeListener(new InternalViewPagerListener());
+ populateTabStrip();
+ }
+ }
+
+ /**
+ * Create a default view to be used for tabs. This is called if a custom tab view is not set via
+ * {@link #setCustomTabView(int, int)}.
+ */
+ protected TextView createDefaultTabView(Context context) {
+ TextView textView = new TextView(context);
+ textView.setGravity(Gravity.CENTER);
+ textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, TAB_VIEW_TEXT_SIZE_SP);
+ textView.setTypeface(Typeface.DEFAULT_BOLD);
+
+ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
+ // If we're running on Honeycomb or newer, then we can use the Theme's
+ // selectableItemBackground to ensure that the View has a pressed state
+ TypedValue outValue = new TypedValue();
+ getContext().getTheme().resolveAttribute(android.R.attr.selectableItemBackground,
+ outValue, true);
+ textView.setBackgroundResource(outValue.resourceId);
+ }
+
+ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
+ // If we're running on ICS or newer, enable all-caps to match the Action Bar tab style
+ textView.setAllCaps(true);
+ }
+
+ int padding = (int) (TAB_VIEW_PADDING_DIPS * getResources().getDisplayMetrics().density);
+ textView.setPadding(padding, padding, padding, padding);
+
+ return textView;
+ }
+
+ private void populateTabStrip() {
+ final PagerAdapter adapter = mViewPager.getAdapter();
+ final View.OnClickListener tabClickListener = new TabClickListener();
+
+ for (int i = 0; i < adapter.getCount(); i++) {
+ View tabView = null;
+ TextView tabTitleView = null;
+
+ if (mTabViewLayoutId != 0) {
+ // If there is a custom tab view layout id set, try and inflate it
+ tabView = LayoutInflater.from(getContext()).inflate(mTabViewLayoutId, mTabStrip,
+ false);
+ tabTitleView = (TextView) tabView.findViewById(mTabViewTextViewId);
+ }
+
+ if (tabView == null) {
+ tabView = createDefaultTabView(getContext());
+ }
+
+ if (tabTitleView == null && TextView.class.isInstance(tabView)) {
+ tabTitleView = (TextView) tabView;
+ }
+
+ tabTitleView.setText(adapter.getPageTitle(i));
+ tabView.setOnClickListener(tabClickListener);
+
+ mTabStrip.addView(tabView);
+ }
+ }
+
+ @Override
+ protected void onAttachedToWindow() {
+ super.onAttachedToWindow();
+
+ if (mViewPager != null) {
+ scrollToTab(mViewPager.getCurrentItem(), 0);
+ }
+ }
+
+ private void scrollToTab(int tabIndex, int positionOffset) {
+ final int tabStripChildCount = mTabStrip.getChildCount();
+ if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) {
+ return;
+ }
+
+ View selectedChild = mTabStrip.getChildAt(tabIndex);
+ if (selectedChild != null) {
+ int targetScrollX = selectedChild.getLeft() + positionOffset;
+
+ if (tabIndex > 0 || positionOffset > 0) {
+ // If we're not at the first child and are mid-scroll, make sure we obey the offset
+ targetScrollX -= mTitleOffset;
+ }
+
+ scrollTo(targetScrollX, 0);
+ }
+ }
+
+ private class InternalViewPagerListener implements ViewPager.OnPageChangeListener {
+ private int mScrollState;
+
+ @Override
+ public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+ int tabStripChildCount = mTabStrip.getChildCount();
+ if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
+ return;
+ }
+
+ mTabStrip.onViewPagerPageChanged(position, positionOffset);
+
+ View selectedTitle = mTabStrip.getChildAt(position);
+ int extraOffset = (selectedTitle != null)
+ ? (int) (positionOffset * selectedTitle.getWidth())
+ : 0;
+ scrollToTab(position, extraOffset);
+
+ if (mViewPagerPageChangeListener != null) {
+ mViewPagerPageChangeListener.onPageScrolled(position, positionOffset,
+ positionOffsetPixels);
+ }
+ }
+
+ @Override
+ public void onPageScrollStateChanged(int state) {
+ mScrollState = state;
+
+ if (mViewPagerPageChangeListener != null) {
+ mViewPagerPageChangeListener.onPageScrollStateChanged(state);
+ }
+ }
+
+ @Override
+ public void onPageSelected(int position) {
+ if (mScrollState == ViewPager.SCROLL_STATE_IDLE) {
+ mTabStrip.onViewPagerPageChanged(position, 0f);
+ scrollToTab(position, 0);
+ }
+
+ if (mViewPagerPageChangeListener != null) {
+ mViewPagerPageChangeListener.onPageSelected(position);
+ }
+ }
+
+ }
+
+ private class TabClickListener implements View.OnClickListener {
+ @Override
+ public void onClick(View v) {
+ for (int i = 0; i < mTabStrip.getChildCount(); i++) {
+ if (v == mTabStrip.getChildAt(i)) {
+ mViewPager.setCurrentItem(i);
+ return;
+ }
+ }
+ }
+ }
+
+}
diff --git a/common/src/java/com/example/android/common/view/SlidingTabStrip.java b/common/src/java/com/example/android/common/view/SlidingTabStrip.java
new file mode 100644
index 0000000..d5bbbae
--- /dev/null
+++ b/common/src/java/com/example/android/common/view/SlidingTabStrip.java
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 2013 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.example.android.common.view;
+
+import android.R;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.util.AttributeSet;
+import android.util.TypedValue;
+import android.view.View;
+import android.widget.LinearLayout;
+
+class SlidingTabStrip extends LinearLayout {
+
+ private static final int DEFAULT_BOTTOM_BORDER_THICKNESS_DIPS = 2;
+ private static final byte DEFAULT_BOTTOM_BORDER_COLOR_ALPHA = 0x26;
+ private static final int SELECTED_INDICATOR_THICKNESS_DIPS = 8;
+ private static final int DEFAULT_SELECTED_INDICATOR_COLOR = 0xFF33B5E5;
+
+ private static final int DEFAULT_DIVIDER_THICKNESS_DIPS = 1;
+ private static final byte DEFAULT_DIVIDER_COLOR_ALPHA = 0x20;
+ private static final float DEFAULT_DIVIDER_HEIGHT = 0.5f;
+
+ private final int mBottomBorderThickness;
+ private final Paint mBottomBorderPaint;
+
+ private final int mSelectedIndicatorThickness;
+ private final Paint mSelectedIndicatorPaint;
+
+ private final int mDefaultBottomBorderColor;
+
+ private final Paint mDividerPaint;
+ private final float mDividerHeight;
+
+ private int mSelectedPosition;
+ private float mSelectionOffset;
+
+ private SlidingTabLayout.TabColorizer mCustomTabColorizer;
+ private final SimpleTabColorizer mDefaultTabColorizer;
+
+ SlidingTabStrip(Context context) {
+ this(context, null);
+ }
+
+ SlidingTabStrip(Context context, AttributeSet attrs) {
+ super(context, attrs);
+ setWillNotDraw(false);
+
+ final float density = getResources().getDisplayMetrics().density;
+
+ TypedValue outValue = new TypedValue();
+ context.getTheme().resolveAttribute(R.attr.colorForeground, outValue, true);
+ final int themeForegroundColor = outValue.data;
+
+ mDefaultBottomBorderColor = setColorAlpha(themeForegroundColor,
+ DEFAULT_BOTTOM_BORDER_COLOR_ALPHA);
+
+ mDefaultTabColorizer = new SimpleTabColorizer();
+ mDefaultTabColorizer.setIndicatorColors(DEFAULT_SELECTED_INDICATOR_COLOR);
+ mDefaultTabColorizer.setDividerColors(setColorAlpha(themeForegroundColor,
+ DEFAULT_DIVIDER_COLOR_ALPHA));
+
+ mBottomBorderThickness = (int) (DEFAULT_BOTTOM_BORDER_THICKNESS_DIPS * density);
+ mBottomBorderPaint = new Paint();
+ mBottomBorderPaint.setColor(mDefaultBottomBorderColor);
+
+ mSelectedIndicatorThickness = (int) (SELECTED_INDICATOR_THICKNESS_DIPS * density);
+ mSelectedIndicatorPaint = new Paint();
+
+ mDividerHeight = DEFAULT_DIVIDER_HEIGHT;
+ mDividerPaint = new Paint();
+ mDividerPaint.setStrokeWidth((int) (DEFAULT_DIVIDER_THICKNESS_DIPS * density));
+ }
+
+ void setCustomTabColorizer(SlidingTabLayout.TabColorizer customTabColorizer) {
+ mCustomTabColorizer = customTabColorizer;
+ invalidate();
+ }
+
+ void setSelectedIndicatorColors(int... colors) {
+ // Make sure that the custom colorizer is removed
+ mCustomTabColorizer = null;
+ mDefaultTabColorizer.setIndicatorColors(colors);
+ invalidate();
+ }
+
+ void setDividerColors(int... colors) {
+ // Make sure that the custom colorizer is removed
+ mCustomTabColorizer = null;
+ mDefaultTabColorizer.setDividerColors(colors);
+ invalidate();
+ }
+
+ void onViewPagerPageChanged(int position, float positionOffset) {
+ mSelectedPosition = position;
+ mSelectionOffset = positionOffset;
+ invalidate();
+ }
+
+ @Override
+ protected void onDraw(Canvas canvas) {
+ final int height = getHeight();
+ final int childCount = getChildCount();
+ final int dividerHeightPx = (int) (Math.min(Math.max(0f, mDividerHeight), 1f) * height);
+ final SlidingTabLayout.TabColorizer tabColorizer = mCustomTabColorizer != null
+ ? mCustomTabColorizer
+ : mDefaultTabColorizer;
+
+ // Thick colored underline below the current selection
+ if (childCount > 0) {
+ View selectedTitle = getChildAt(mSelectedPosition);
+ int left = selectedTitle.getLeft();
+ int right = selectedTitle.getRight();
+ int color = tabColorizer.getIndicatorColor(mSelectedPosition);
+
+ if (mSelectionOffset > 0f && mSelectedPosition < (getChildCount() - 1)) {
+ int nextColor = tabColorizer.getIndicatorColor(mSelectedPosition + 1);
+ if (color != nextColor) {
+ color = blendColors(nextColor, color, mSelectionOffset);
+ }
+
+ // 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);
+ }
+
+ mSelectedIndicatorPaint.setColor(color);
+
+ canvas.drawRect(left, height - mSelectedIndicatorThickness, right,
+ height, mSelectedIndicatorPaint);
+ }
+
+ // Thin underline along the entire bottom edge
+ canvas.drawRect(0, height - mBottomBorderThickness, getWidth(), height, mBottomBorderPaint);
+
+ // Vertical separators between the titles
+ int separatorTop = (height - dividerHeightPx) / 2;
+ for (int i = 0; i < childCount - 1; i++) {
+ View child = getChildAt(i);
+ mDividerPaint.setColor(tabColorizer.getDividerColor(i));
+ canvas.drawLine(child.getRight(), separatorTop, child.getRight(),
+ separatorTop + dividerHeightPx, mDividerPaint);
+ }
+ }
+
+ /**
+ * Set the alpha value of the {@code color} to be the given {@code alpha} value.
+ */
+ private static int setColorAlpha(int color, byte alpha) {
+ return Color.argb(alpha, Color.red(color), Color.green(color), Color.blue(color));
+ }
+
+ /**
+ * Blend {@code color1} and {@code color2} using the given ratio.
+ *
+ * @param ratio of which to blend. 1.0 will return {@code color1}, 0.5 will give an even blend,
+ * 0.0 will return {@code color2}.
+ */
+ private static int blendColors(int color1, int color2, float ratio) {
+ final float inverseRation = 1f - ratio;
+ float r = (Color.red(color1) * ratio) + (Color.red(color2) * inverseRation);
+ float g = (Color.green(color1) * ratio) + (Color.green(color2) * inverseRation);
+ float b = (Color.blue(color1) * ratio) + (Color.blue(color2) * inverseRation);
+ return Color.rgb((int) r, (int) g, (int) b);
+ }
+
+ private static class SimpleTabColorizer implements SlidingTabLayout.TabColorizer {
+ private int[] mIndicatorColors;
+ private int[] mDividerColors;
+
+ @Override
+ public final int getIndicatorColor(int position) {
+ return mIndicatorColors[position % mIndicatorColors.length];
+ }
+
+ @Override
+ public final int getDividerColor(int position) {
+ return mDividerColors[position % mDividerColors.length];
+ }
+
+ void setIndicatorColors(int... colors) {
+ mIndicatorColors = colors;
+ }
+
+ void setDividerColors(int... colors) {
+ mDividerColors = colors;
+ }
+ }
+}
\ No newline at end of file
