Java tutorial
/* * Copyright (C) 2013 Andreas Stuetz <andreas.stuetz@gmail.com> * * 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.orange.ocara.ui.view; import android.annotation.SuppressLint; import android.content.Context; import android.content.res.ColorStateList; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Paint.Style; import android.graphics.Typeface; import android.os.Build; import android.os.Parcel; import android.os.Parcelable; import android.support.v4.view.ViewPager; import android.text.TextUtils; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.util.TypedValue; import android.view.Gravity; import android.view.View; import android.view.ViewTreeObserver.OnGlobalLayoutListener; import android.widget.LinearLayout; import android.widget.TextView; import com.orange.ocara.R; public class PagerSlidingTabStrip extends LinearLayout { // @formatter:off private static final int[] ATTRS = new int[] { android.R.attr.textSize, android.R.attr.textColor, }; // @formatter:on private LayoutParams tabLayoutParams; private final PageListener pageListener = new PageListener(); public ViewPager.OnPageChangeListener delegatePageListener; private LinearLayout tabsContainer; private ViewPager pager; private int tabCount; private int currentPosition = 0; private float currentPositionOffset = 0f; private Paint rectPaint; private Paint dividerPaint; private int indicatorColor = 0xFF666666; private int underlineColor = 0x1A000000; private int dividerColor = 0x1A000000; private int indicatorHeight = 8; private int underlineHeight = 2; private int dividerPadding = 12; private int tabPadding = 24; private int dividerWidth = 1; private int tabTextSize = 12; private ColorStateList tabTextColor; private int tabBackgroundResId = R.drawable.tab_background; public PagerSlidingTabStrip(Context context) { this(context, null); } public PagerSlidingTabStrip(Context context, AttributeSet attrs) { this(context, attrs, 0); } public PagerSlidingTabStrip(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); setWillNotDraw(false); DisplayMetrics dm = getResources().getDisplayMetrics(); indicatorHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, indicatorHeight, dm); underlineHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, underlineHeight, dm); dividerPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dividerPadding, dm); tabPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, tabPadding, dm); dividerWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dividerWidth, dm); tabTextSize = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, tabTextSize, dm); // get system attrs (android:textSize and android:textColor) TypedArray a = context.obtainStyledAttributes(attrs, ATTRS); tabTextSize = a.getDimensionPixelSize(0, tabTextSize); tabTextColor = a.getColorStateList(1); a.recycle(); // get custom attrs a = context.obtainStyledAttributes(attrs, R.styleable.PagerSlidingTabStrip); indicatorColor = a.getColor(R.styleable.PagerSlidingTabStrip_indicatorColor, indicatorColor); underlineColor = a.getColor(R.styleable.PagerSlidingTabStrip_underlineColor, underlineColor); dividerColor = a.getColor(R.styleable.PagerSlidingTabStrip_dividerColor, dividerColor); indicatorHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_indicatorHeight, indicatorHeight); underlineHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_underlineHeight, underlineHeight); dividerPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_dividerPaddingTabStrip, dividerPadding); tabPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_tabPaddingLeftRight, tabPadding); tabBackgroundResId = a.getResourceId(R.styleable.PagerSlidingTabStrip_tabBackground, tabBackgroundResId); a.recycle(); rectPaint = new Paint(); rectPaint.setAntiAlias(true); rectPaint.setStyle(Style.FILL); dividerPaint = new Paint(); dividerPaint.setAntiAlias(true); dividerPaint.setStrokeWidth(dividerWidth); tabLayoutParams = new LayoutParams(0, LayoutParams.MATCH_PARENT, 1.0f); tabsContainer = new LinearLayout(context); tabsContainer.setOrientation(LinearLayout.HORIZONTAL); tabsContainer.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); addView(tabsContainer, new LayoutParams(0, LayoutParams.MATCH_PARENT, 1)); } /** * To set the ViewPager. * * @param pager ViewPager associated */ public void setViewPager(ViewPager pager) { this.pager = pager; if (pager.getAdapter() == null) { throw new IllegalStateException("ViewPager does not have adapter instance."); } pager.setOnPageChangeListener(pageListener); notifyDataSetChanged(); } /** * To set a delegate OnPageChangeListener * * @param listener OnPageChangeListener */ public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) { this.delegatePageListener = listener; } /** * To force the data change. */ public void notifyDataSetChanged() { tabsContainer.removeAllViews(); tabCount = pager.getAdapter().getCount(); for (int i = 0; i < tabCount; i++) { addTextTab(i, pager.getAdapter().getPageTitle(i).toString()); } updateTabStates(currentPosition); getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() { @SuppressWarnings("deprecation") @SuppressLint("NewApi") @Override public void onGlobalLayout() { if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) { getViewTreeObserver().removeGlobalOnLayoutListener(this); } else { getViewTreeObserver().removeOnGlobalLayoutListener(this); } currentPosition = pager.getCurrentItem(); } }); } private void addTextTab(final int position, String title) { TextView tab = new TextView(getContext()); tab.setText(title); tab.setGravity(Gravity.CENTER); tab.setSingleLine(); tab.setBackgroundResource(tabBackgroundResId); tab.setTextColor(tabTextColor); tab.setTextSize(TypedValue.COMPLEX_UNIT_PX, tabTextSize); tab.setEllipsize(TextUtils.TruncateAt.MARQUEE); tab.setAllCaps(true); addTab(position, tab); } private void addTab(final int position, View tab) { tab.setFocusable(true); tab.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { pager.setCurrentItem(position); } }); tab.setPadding(tabPadding, 0, tabPadding, 0); tabsContainer.addView(tab, position, tabLayoutParams); } private void updateTabStates(int selectedPosition) { for (int i = 0; i < tabCount; i++) { boolean isSelected = (i == selectedPosition); View v = tabsContainer.getChildAt(i); TextView tab = (TextView) v; if (isSelected == true) { tab.setTypeface(Typeface.DEFAULT_BOLD); } else { tab.setTypeface(Typeface.DEFAULT); } } } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (isInEditMode() || tabCount == 0) { return; } final int height = getHeight(); // draw underline rectPaint.setColor(underlineColor); canvas.drawRect(0, height - underlineHeight, getWidth(), height, rectPaint); // draw indicator line rectPaint.setColor(indicatorColor); // default: line below current tab View currentTab = tabsContainer.getChildAt(currentPosition); float lineLeft = currentTab.getLeft(); float lineRight = currentTab.getRight(); // if there is an offset, start interpolating left and right coordinates between current and next tab if (currentPositionOffset > 0f && currentPosition < tabCount - 1) { View nextTab = tabsContainer.getChildAt(currentPosition + 1); final float nextTabLeft = nextTab.getLeft(); final float nextTabRight = nextTab.getRight(); lineLeft = (currentPositionOffset * nextTabLeft + (1f - currentPositionOffset) * lineLeft); lineRight = (currentPositionOffset * nextTabRight + (1f - currentPositionOffset) * lineRight); } float tabsLeft = tabsContainer.getLeft(); canvas.drawRect(lineLeft + tabsLeft, height - indicatorHeight, lineRight + tabsLeft, height, rectPaint); // draw divider dividerPaint.setColor(dividerColor); for (int i = 0; i < tabCount - 1; i++) { View tab = tabsContainer.getChildAt(i); canvas.drawLine(tab.getRight(), dividerPadding, tab.getRight(), height - dividerPadding, dividerPaint); } } private class PageListener implements ViewPager.OnPageChangeListener { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { currentPosition = position; currentPositionOffset = positionOffset; invalidate(); if (delegatePageListener != null) { delegatePageListener.onPageScrolled(position, positionOffset, positionOffsetPixels); } } @Override public void onPageScrollStateChanged(int state) { if (delegatePageListener != null) { delegatePageListener.onPageScrollStateChanged(state); } } @Override public void onPageSelected(int position) { updateTabStates(position); if (delegatePageListener != null) { delegatePageListener.onPageSelected(position); } } } @Override public void onRestoreInstanceState(Parcelable state) { SavedState savedState = (SavedState) state; super.onRestoreInstanceState(savedState.getSuperState()); currentPosition = savedState.currentPosition; requestLayout(); } @Override public Parcelable onSaveInstanceState() { Parcelable superState = super.onSaveInstanceState(); SavedState savedState = new SavedState(superState); savedState.currentPosition = currentPosition; return savedState; } static class SavedState extends BaseSavedState { int currentPosition; public SavedState(Parcelable superState) { super(superState); } private SavedState(Parcel in) { super(in); currentPosition = in.readInt(); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeInt(currentPosition); } public static final Creator<SavedState> CREATOR = new Creator<SavedState>() { @Override public SavedState createFromParcel(Parcel in) { return new SavedState(in); } @Override public SavedState[] newArray(int size) { return new SavedState[size]; } }; } }