/*
* 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 in.co.praveenkumar.mdroid.view;
import in.co.praveenkumar.R;
import android.annotation.SuppressLint;
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 = 14;
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)}.
*/
@SuppressLint({ "InlinedApi", "NewApi" })
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);
// Setting selectable background for tab items.
// 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);
}
updateTabTextColors(0);
}
@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);
}
updateTabTextColors(position);
}
}
/**
* Custom class to work with Text colors for various states
*
* @param position
* current tab position
*/
public void updateTabTextColors(int position) {
// Update text color
for (int i = 0; i < mTabStrip.getChildCount(); i++) {
TextView tv = (TextView) mTabStrip.getChildAt(i);
if (i == position) {
tv.setTextColor(getResources().getColor(R.color.white));
} else {
tv.setTextColor(getResources().getColor(R.color.tab_unselected));
}
}
}
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;
}
}
}
}
}