/*
* Copyright 2014 Google Inc. All rights reserved.
*
* 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 org.nativescript.widgets;
import android.content.Context;
import android.graphics.Typeface;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
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...)}.
* The alternative is via the {@link TabColorizer} interface which provides you
* complete control over which color is used for any individual position.
* <p>
*/
public class TabLayout 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);
}
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 static final int TEXT_MAX_WIDTH = 180;
private static final int SMALL_MIN_HEIGHT = 48;
private static final int LARGE_MIN_HEIGHT = 72;
private int mTitleOffset;
private boolean mDistributeEvenly = true;
private TabItemSpec[] mTabItems;
private ViewPager mViewPager;
private SparseArray<String> mContentDescriptions = new SparseArray<String>();
private ViewPager.OnPageChangeListener mViewPagerPageChangeListener;
private final TabStrip mTabStrip;
public TabLayout(Context context) {
this(context, null);
}
public TabLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public TabLayout(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 TabStrip(context);
addView(mTabStrip, LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
}
/**
* Set the custom {@link TabColorizer} to be used.
*
* If you only require simple customisation then you can use
* {@link #setSelectedIndicatorColors(int...)} to achieve similar effects.
*/
public void setCustomTabColorizer(TabColorizer tabColorizer) {
mTabStrip.setCustomTabColorizer(tabColorizer);
}
public void setDistributeEvenly(boolean distributeEvenly) {
mDistributeEvenly = distributeEvenly;
}
/**
* 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);
this.mSelectedIndicatorColors = colors;
}
private int[] mSelectedIndicatorColors;
public int[] getSelectedIndicatorColors() {
return this.mSelectedIndicatorColors;
}
public void setTabTextColor(int color){
mTabStrip.setTabTextColor(color);
}
public int getTabTextColor(){
return mTabStrip.getTabTextColor();
}
public void setSelectedTabTextColor(int color){
mTabStrip.setSelectedTabTextColor(color);
}
public int getSelectedTabTextColor(){
return mTabStrip.getSelectedTabTextColor();
}
public void setTabTextFontSize(float fontSize){
mTabStrip.setTabTextFontSize(fontSize);
}
public float getTabTextFontSize(){
return mTabStrip.getTabTextFontSize();
}
/**
* Set the {@link ViewPager.OnPageChangeListener}. When using
* {@link TabLayout} 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;
}
/**
* 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) {
this.setItems(null, viewPager);
}
public void setItems(TabItemSpec[] items, ViewPager viewPager) {
mTabStrip.removeAllViews();
mViewPager = viewPager;
mTabItems = items;
if (viewPager != null) {
viewPager.addOnPageChangeListener(new InternalViewPagerListener());
populateTabStrip();
}
}
/**
* Updates the UI of an item at specified index
*/
public void updateItemAt(int position, TabItemSpec tabItem) {
LinearLayout ll = (LinearLayout)mTabStrip.getChildAt(position);
ImageView imgView = (ImageView)ll.getChildAt(0);
TextView textView = (TextView)ll.getChildAt(1);
this.setupItem(ll, textView, imgView, tabItem);
}
/**
* Gets the TextView for tab item at index
*/
public TextView getTextViewForItemAt(int index){
LinearLayout ll = this.getViewForItemAt(index);
return (ll != null) ? (TextView)ll.getChildAt(1) : null;
}
/**
* Gets the LinearLayout container for tab item at index
*/
public LinearLayout getViewForItemAt(int index){
LinearLayout result = null;
if(this.mTabStrip.getChildCount() > index){
result = (LinearLayout)this.mTabStrip.getChildAt(index);
}
return result;
}
/**
* Gets the number of realized tabs.
*/
public int getItemCount(){
return this.mTabStrip.getChildCount();
}
/**
* Create a default view to be used for tabs.
*/
protected View createDefaultTabView(Context context, TabItemSpec tabItem) {
float density = getResources().getDisplayMetrics().density;
int padding = (int) (TAB_VIEW_PADDING_DIPS * density);
LinearLayout ll = new LinearLayout(context);
ll.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.MATCH_PARENT));
ll.setGravity(Gravity.CENTER);
ll.setOrientation(LinearLayout.VERTICAL);
TypedValue outValue = new TypedValue();
getContext().getTheme().resolveAttribute(android.R.attr.selectableItemBackground, outValue, true);
ll.setBackgroundResource(outValue.resourceId);
ImageView imgView = new ImageView(context);
imgView.setScaleType(ScaleType.FIT_CENTER);
LinearLayout.LayoutParams imgLP = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
imgLP.gravity = Gravity.CENTER;
imgView.setLayoutParams(imgLP);
TextView textView = new TextView(context);
textView.setGravity(Gravity.CENTER);
textView.setMaxWidth((int) (TEXT_MAX_WIDTH * density));
textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, TAB_VIEW_TEXT_SIZE_SP);
textView.setTypeface(Typeface.DEFAULT_BOLD);
textView.setEllipsize(TextUtils.TruncateAt.END);
textView.setAllCaps(true);
textView.setMaxLines(2);
textView.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
textView.setPadding(padding, 0, padding, 0);
this.setupItem(ll, textView, imgView, tabItem);
ll.addView(imgView);
ll.addView(textView);
return ll;
}
private void setupItem(LinearLayout ll, TextView textView,ImageView imgView, TabItemSpec tabItem){
float density = getResources().getDisplayMetrics().density;
if (tabItem.iconId != 0) {
imgView.setImageResource(tabItem.iconId);
imgView.setVisibility(VISIBLE);
} else if (tabItem.iconDrawable != null) {
imgView.setImageDrawable(tabItem.iconDrawable);
imgView.setVisibility(VISIBLE);
} else {
imgView.setVisibility(GONE);
}
if (tabItem.title != null && !tabItem.title.isEmpty()) {
textView.setText(tabItem.title);
textView.setVisibility(VISIBLE);
} else {
textView.setVisibility(GONE);
}
if (imgView.getVisibility() == VISIBLE && textView.getVisibility() == VISIBLE) {
ll.setMinimumHeight((int) (LARGE_MIN_HEIGHT * density));
} else {
ll.setMinimumHeight((int) (SMALL_MIN_HEIGHT * density));
}
if (mDistributeEvenly) {
LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) ll.getLayoutParams();
lp.width = 0;
lp.weight = 1;
}
}
private void populateTabStrip() {
final PagerAdapter adapter = mViewPager.getAdapter();
final OnClickListener tabClickListener = new TabClickListener();
for (int i = 0; i < adapter.getCount(); i++) {
View tabView = null;
TabItemSpec tabItem;
if (this.mTabItems != null && this.mTabItems.length > i) {
tabItem = this.mTabItems[i];
} else {
tabItem = new TabItemSpec();
tabItem.title = adapter.getPageTitle(i).toString();
}
tabView = createDefaultTabView(getContext(), tabItem);
tabView.setOnClickListener(tabClickListener);
String desc = mContentDescriptions.get(i, null);
if (desc != null) {
tabView.setContentDescription(desc);
}
mTabStrip.addView(tabView);
if (i == mViewPager.getCurrentItem()) {
tabView.setSelected(true);
}
}
}
public void setContentDescription(int i, String desc) {
mContentDescriptions.put(i, desc);
}
@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);
}
for (int i = 0; i < mTabStrip.getChildCount(); i++) {
mTabStrip.getChildAt(i).setSelected(position == i);
}
if (mViewPagerPageChangeListener != null) {
mViewPagerPageChangeListener.onPageSelected(position);
}
}
}
private class TabClickListener implements OnClickListener {
@Override
public void onClick(View v) {
for (int i = 0; i < mTabStrip.getChildCount(); i++) {
if (v == mTabStrip.getChildAt(i)) {
mViewPager.setCurrentItem(i);
return;
}
}
}
}
}
