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.twi.awayday2014.view.custom; import android.annotation.SuppressLint; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Color; 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.support.v4.view.ViewPager.OnPageChangeListener; 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.HorizontalScrollView; import android.widget.LinearLayout; import android.widget.TextView; import com.twi.awayday2014.R; public class PagerSlidingTabStrip extends HorizontalScrollView { // @formatter:off private static final int[] ATTRS = new int[] { android.R.attr.textSize, android.R.attr.textColor }; // @formatter:on private LinearLayout.LayoutParams defaultTabLayoutParams; private LinearLayout.LayoutParams expandedTabLayoutParams; private final PageListener pageListener = new PageListener(); public 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 boolean checkedTabWidths = false; private int indicatorColor = 0xFF666666; private int underlineColor = 0x1A000000; private int dividerColor1 = 0x1A000000; private int dividerColor2 = 0x1A000000; private boolean shouldExpand = false; private int scrollOffset = 52; private int indicatorHeight = 8; private int underlineHeight = 2; private int dividerPadding = 12; private int tabPadding = 24; private int dividerWidth = 2; private int tabTextSize = 12; private int tabTextColor = 0xFF666666; private int selectedTextColor = 0xFF666666; private Typeface tabTypeface = null; private int tabTypefaceStyle = Typeface.BOLD; private int lastScrollX = 0; private int tabBackgroundResId = R.drawable.page_indicator_tab_selector; 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); setFillViewport(true); setWillNotDraw(false); tabsContainer = new LinearLayout(context); tabsContainer.setOrientation(LinearLayout.HORIZONTAL); tabsContainer.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); addView(tabsContainer); DisplayMetrics dm = getResources().getDisplayMetrics(); scrollOffset = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, scrollOffset, dm); 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.getColor(1, tabTextColor); 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); dividerColor1 = a.getColor(R.styleable.PagerSlidingTabStrip_dividerColor1, dividerColor1); dividerColor2 = a.getColor(R.styleable.PagerSlidingTabStrip_dividerColor2, dividerColor2); indicatorHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_indicatorHeight, indicatorHeight); underlineHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_underlineHeight, underlineHeight); dividerPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_stripDividerPadding, dividerPadding); tabPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_tabPaddingLeftRight, tabPadding); tabBackgroundResId = a.getResourceId(R.styleable.PagerSlidingTabStrip_tabBackground, tabBackgroundResId); shouldExpand = a.getBoolean(R.styleable.PagerSlidingTabStrip_shouldExpand, shouldExpand); scrollOffset = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_scrollOffset, scrollOffset); a.recycle(); rectPaint = new Paint(); rectPaint.setAntiAlias(true); rectPaint.setStyle(Style.FILL); dividerPaint = new Paint(); dividerPaint.setAntiAlias(true); dividerPaint.setStrokeWidth(dividerWidth / 2); defaultTabLayoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT); expandedTabLayoutParams = new LinearLayout.LayoutParams(0, LayoutParams.MATCH_PARENT, 1.0f); } 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(); } public void setOnPageChangeListener(OnPageChangeListener listener) { this.delegatePageListener = listener; } public void notifyDataSetChanged() { tabsContainer.removeAllViews(); tabCount = pager.getAdapter().getCount(); for (int i = 0; i < tabCount; i++) { addTab(i, pager.getAdapter().getPageTitle(i).toString()); } updateTabStyles(); checkedTabWidths = false; 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(); scrollToChild(currentPosition, 0); } }); } private void addTab(final int position, String title) { TextView tab = new TextView(getContext()); tab.setText(title); tab.setFocusable(true); tab.setGravity(Gravity.CENTER); tab.setSingleLine(); tab.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { pager.setCurrentItem(position); } }); tabsContainer.addView(tab); } private void updateTabStyles() { for (int i = 0; i < tabCount; i++) { TextView tab = (TextView) tabsContainer.getChildAt(i); tab.setLayoutParams(defaultTabLayoutParams); tab.setBackgroundResource(tabBackgroundResId); if (shouldExpand) { tab.setPadding(0, 0, 0, 0); } else { tab.setPadding(tabPadding, 0, tabPadding, 0); } tab.setTextSize(TypedValue.COMPLEX_UNIT_PX, tabTextSize); tab.setTypeface(tabTypeface, tabTypefaceStyle); tab.setTextColor(tabTextColor); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (!shouldExpand || MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.UNSPECIFIED) { return; } int myWidth = getMeasuredWidth(); int childWidth = 0; for (int i = 0; i < tabCount; i++) { childWidth += tabsContainer.getChildAt(i).getMeasuredWidth(); } if (!checkedTabWidths && childWidth > 0 && myWidth > 0) { if (childWidth <= myWidth) { for (int i = 0; i < tabCount; i++) { tabsContainer.getChildAt(i).setLayoutParams(expandedTabLayoutParams); } } checkedTabWidths = true; } } private void scrollToChild(int position, int offset) { int newScrollX = tabsContainer.getChildAt(position).getLeft() + offset; if (position > 0 || offset > 0) { newScrollX -= scrollOffset; } if (newScrollX != lastScrollX) { lastScrollX = newScrollX; scrollTo(newScrollX, 0); } } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (isInEditMode() || tabCount == 0) { return; } final int height = getHeight(); // draw indicator line rectPaint.setColor(indicatorColor); // default: line below current tab View currentTab = tabsContainer.getChildAt(currentPosition); int lineLeft = currentTab.getLeft(); int 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); int nextTabLeft = nextTab.getLeft(); int nextTabRight = nextTab.getRight(); lineLeft = (int) (currentPositionOffset * nextTabLeft + (1f - currentPositionOffset) * lineLeft); lineRight = (int) (currentPositionOffset * nextTabRight + (1f - currentPositionOffset) * lineRight); } canvas.drawRect(lineLeft, height - indicatorHeight, lineRight, height, rectPaint); // draw underline rectPaint.setColor(underlineColor); canvas.drawRect(0, height - underlineHeight, tabsContainer.getWidth(), height, rectPaint); // draw divider for (int i = 0; i < tabCount - 1; i++) { View tab = tabsContainer.getChildAt(i); dividerPaint.setColor(dividerColor1); canvas.drawLine(tab.getRight(), dividerPadding, tab.getRight(), height - dividerPadding, dividerPaint); dividerPaint.setColor(dividerColor2); canvas.drawLine(tab.getRight() + dividerWidth / 2, dividerPadding, tab.getRight() + dividerWidth / 2, height - dividerPadding, dividerPaint); } } public void makeCurrentSelected(int currentPosition) { selectTextFor(currentPosition); } private class PageListener implements OnPageChangeListener { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { currentPosition = position; currentPositionOffset = positionOffset; scrollToChild(position, (int) (positionOffset * tabsContainer.getChildAt(position).getWidth())); invalidate(); if (delegatePageListener != null) { delegatePageListener.onPageScrolled(position, positionOffset, positionOffsetPixels); } } @Override public void onPageScrollStateChanged(int state) { if (state == ViewPager.SCROLL_STATE_IDLE) { scrollToChild(pager.getCurrentItem(), 0); } if (delegatePageListener != null) { delegatePageListener.onPageScrollStateChanged(state); } } @Override public void onPageSelected(int position) { selectTextFor(position); if (delegatePageListener != null) { delegatePageListener.onPageSelected(position); } } } private void selectTextFor(int position) { for (int i = 0; i < tabCount; i++) { TextView tab = (TextView) tabsContainer.getChildAt(i); tab.setTextColor(tabTextColor); } TextView tab = (TextView) tabsContainer.getChildAt(position); tab.setTextColor(selectedTextColor); } public void setIndicatorColor(int indicatorColor) { this.indicatorColor = indicatorColor; invalidate(); } public void setIndicatorColorResource(int resId) { this.indicatorColor = getResources().getColor(resId); invalidate(); } public int getIndicatorColor() { return this.indicatorColor; } public void setIndicatorHeight(int indicatorLineHeightPx) { this.indicatorHeight = indicatorLineHeightPx; invalidate(); } public int getIndicatorHeight() { return indicatorHeight; } public void setUnderlineColor(int underlineColor) { this.underlineColor = underlineColor; invalidate(); } public void setUnderlineColorResource(int resId) { this.underlineColor = getResources().getColor(resId); invalidate(); } public int getUnderlineColor() { return underlineColor; } public void setDividerColor1(int dividerColor) { this.dividerColor1 = dividerColor; invalidate(); } public void setDividerColor2(int dividerColor) { this.dividerColor2 = dividerColor; invalidate(); } public void setDividerColor1Resource(int resId) { this.dividerColor1 = getResources().getColor(resId); invalidate(); } public void setDividerColor2Resource(int resId) { this.dividerColor2 = getResources().getColor(resId); invalidate(); } public int getDividerColor1() { return dividerColor1; } public int getDividerColor2() { return dividerColor1; } public void setUnderlineHeight(int underlineHeightPx) { this.underlineHeight = underlineHeightPx; invalidate(); } public int getUnderlineHeight() { return underlineHeight; } public void setDividerPadding(int dividerPaddingPx) { this.dividerPadding = dividerPaddingPx; invalidate(); } public int getDividerPadding() { return dividerPadding; } public void setScrollOffset(int scrollOffsetPx) { this.scrollOffset = scrollOffsetPx; invalidate(); } public int getScrollOffset() { return scrollOffset; } public void setShouldExpand(boolean shouldExpand) { this.shouldExpand = shouldExpand; requestLayout(); } public boolean getShuldExpand() { return shouldExpand; } public void setTextSize(int textSizePx) { this.tabTextSize = textSizePx; updateTabStyles(); } public int getTextSize() { return tabTextSize; } public void setTextColor(int textColor) { this.tabTextColor = textColor; updateTabStyles(); } public void setSelectedTextColor(int textColor) { this.selectedTextColor = textColor; } public void setTextColorResource(int resId) { this.tabTextColor = getResources().getColor(resId); updateTabStyles(); } public int getTextColor() { return tabTextColor; } public void setTypeface(Typeface typeface, int style) { this.tabTypeface = typeface; this.tabTypefaceStyle = style; updateTabStyles(); } public void setTabBackground(int resId) { this.tabBackgroundResId = resId; } public int getTabBackground() { return tabBackgroundResId; } public void setTabPaddingLeftRight(int paddingPx) { this.tabPadding = paddingPx; updateTabStyles(); } public int getTabPaddingLeftRight() { return tabPadding; } @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]; } }; } @Override public int getSolidColor() { return Color.parseColor("#000000"); } }