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.chenl.widgets.flippablestackview.indicator; 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.Color; import android.graphics.Paint; import android.graphics.Paint.Style; import android.graphics.Typeface; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.StateListDrawable; 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.ImageButton; import android.widget.LinearLayout; import android.widget.TextView; import com.chenl.widgets.R; import com.chenl.widgets.flippablestackview.OrientedViewPager; import java.util.Locale; public class OrientedPagerSlidingTabLayout extends HorizontalScrollView { public interface IconTabProvider { public int getPageIconResId(int position); } private LinearLayout.LayoutParams defaultTabLayoutParams; private LinearLayout.LayoutParams expandedTabLayoutParams; private final PageListener pageListener = new PageListener(); public OnPageChangeListener delegatePageListener; private LinearLayout tabsContainer; private OrientedViewPager mPager; private int tabCount; private int mCurrentPosition = 0; private float currentPositionOffset = 0f; private Paint rectPaint; private Paint dividerPaint; private int indicatorColor = 0xFF666666; private int underlineColor = 0x1A000000; private int dividerColor = 0x1A000000; private boolean shouldExpand = false; private boolean textAllCaps = true; private int scrollOffset = 52; private int indicatorHeight = 8; private int underlineHeight = 2; private int dividerPadding = 12; private int tabMargins = 0; private int tabPadding = 24; private int dividerWidth = 1; private int tabTextSize = 12; private ColorStateList tabTextColor = ColorStateList.valueOf(android.R.color.white); private Typeface tabTypeface = null; private int tabTypefaceStyle = Typeface.BOLD; private int lastScrollX = 0; private int tabBackgroundResId = -1; private StateListDrawable mTabBackgroundRes = createStateDrawable(); private Locale locale; public OrientedPagerSlidingTabLayout(Context context) { this(context, null); } public OrientedPagerSlidingTabLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public OrientedPagerSlidingTabLayout(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 displayMetrics = getResources().getDisplayMetrics(); scrollOffset = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, scrollOffset, displayMetrics); indicatorHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, indicatorHeight, displayMetrics); underlineHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, underlineHeight, displayMetrics); dividerPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dividerPadding, displayMetrics); tabPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, tabPadding, displayMetrics); dividerWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dividerWidth, displayMetrics); tabTextSize = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, tabTextSize, displayMetrics); TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.OrientedPagerSlidingTabLayout); tabTextSize = typedArray.getDimensionPixelSize(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutTextSize, tabTextSize); tabTextColor = typedArray.getColorStateList(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutTextColor); indicatorColor = typedArray.getColor(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutIndicatorColor, indicatorColor); underlineColor = typedArray.getColor(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutUnderlineColor, underlineColor); dividerColor = typedArray.getColor(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutDividerColor, dividerColor); indicatorHeight = typedArray.getDimensionPixelSize( R.styleable.OrientedPagerSlidingTabLayout_tabLayoutIndicatorHeight, indicatorHeight); underlineHeight = typedArray.getDimensionPixelSize( R.styleable.OrientedPagerSlidingTabLayout_tabLayoutUnderlineHeight, underlineHeight); dividerPadding = typedArray.getDimensionPixelSize( R.styleable.OrientedPagerSlidingTabLayout_tabLayoutDividerPadding, dividerPadding); tabPadding = typedArray.getDimensionPixelSize( R.styleable.OrientedPagerSlidingTabLayout_tabLayoutPaddingLeftRight, tabPadding); tabBackgroundResId = typedArray.getResourceId(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutBackground, tabBackgroundResId); shouldExpand = typedArray.getBoolean(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutShouldExpand, shouldExpand); scrollOffset = typedArray.getDimensionPixelSize( R.styleable.OrientedPagerSlidingTabLayout_tabLayoutScrollOffset, scrollOffset); textAllCaps = typedArray.getBoolean(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutTextAllCaps, textAllCaps); tabMargins = typedArray.getDimensionPixelSize(R.styleable.OrientedPagerSlidingTabLayout_tabLayoutMargins, tabMargins); typedArray.recycle(); rectPaint = new Paint(); rectPaint.setAntiAlias(true); rectPaint.setStyle(Style.FILL); dividerPaint = new Paint(); dividerPaint.setAntiAlias(true); dividerPaint.setStrokeWidth(dividerWidth); defaultTabLayoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT); expandedTabLayoutParams = new LinearLayout.LayoutParams(0, LayoutParams.MATCH_PARENT, 1.0f); if (locale == null) { locale = getResources().getConfiguration().locale; } } public void setOrientedViewPager(OrientedViewPager pager) { this.mPager = 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 = mPager.getAdapter().getCount(); for (int i = 0; i < tabCount; i++) { if (mPager.getAdapter() instanceof IconTabProvider) { addIconTab(i, ((IconTabProvider) mPager.getAdapter()).getPageIconResId(i)); } else { addTextTab(i, mPager.getAdapter().getPageTitle(i).toString()); } } updateTabStyles(); 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); } mCurrentPosition = mPager.getCurrentItem(); scrollToChild(mCurrentPosition, 0); } }); } private void addTextTab(final int position, String title) { TextView tab = new TextView(getContext()); tab.setText(title); tab.setGravity(Gravity.CENTER); tab.setMaxLines(2); addTab(position, tab); } private void addIconTab(final int position, int resId) { ImageButton tab = new ImageButton(getContext()); tab.setImageResource(resId); addTab(position, tab); } private void addTab(final int position, View tab) { tab.setFocusable(true); tab.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { mPager.setCurrentItem(position); } }); tab.setPadding(tabPadding, 0, tabPadding, 0); LinearLayout.LayoutParams params = shouldExpand ? expandedTabLayoutParams : defaultTabLayoutParams; params.setMargins(tabMargins, tabMargins, tabMargins, tabMargins); tabsContainer.addView(tab, position, params); } private void updateTabStyles() { for (int i = 0; i < tabCount; i++) { View childView = tabsContainer.getChildAt(i); if (tabBackgroundResId == -1) { childView.setBackgroundDrawable(mTabBackgroundRes); } else { childView.setBackgroundResource(tabBackgroundResId); } if (childView instanceof TextView) { TextView tab = (TextView) childView; tab.setTextSize(tabTextSize); tab.setTextColor(tabTextColor); if (textAllCaps) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { tab.setAllCaps(true); } else { tab.setText(tab.getText().toString().toUpperCase(locale)); } } } } } private void scrollToChild(int position, int offset) { if (tabCount == 0) { return; } 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; } if (underlineHeight > 0) { final int height = getHeight(); // 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); } // draw underline rectPaint.setColor(underlineColor); canvas.drawRect(0, height - underlineHeight, tabsContainer.getWidth(), height, rectPaint); } if (indicatorHeight > 0) { final int height = getHeight(); // draw indicator line rectPaint.setColor(indicatorColor); // default: line below current tab View currentTab = tabsContainer.getChildAt(mCurrentPosition); 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 && mCurrentPosition < tabCount - 1) { View nextTab = tabsContainer.getChildAt(mCurrentPosition + 1); final float nextTabLeft = nextTab.getLeft(); final float nextTabRight = nextTab.getRight(); lineLeft = (currentPositionOffset * nextTabLeft + (1f - currentPositionOffset) * lineLeft); lineRight = (currentPositionOffset * nextTabRight + (1f - currentPositionOffset) * lineRight); } canvas.drawRect(lineLeft, height - indicatorHeight, lineRight, height, rectPaint); } } private class PageListener implements OnPageChangeListener { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { tabsContainer.getChildAt(mCurrentPosition).setSelected(false); mCurrentPosition = position; tabsContainer.getChildAt(mCurrentPosition).setSelected(true); 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(mPager.getCurrentItem(), 0); } if (delegatePageListener != null) { delegatePageListener.onPageScrollStateChanged(state); } } @Override public void onPageSelected(int position) { if (delegatePageListener != null) { delegatePageListener.onPageSelected(position); } } } 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 setDividerColor(int dividerColor) { this.dividerColor = dividerColor; invalidate(); } public void setDividerColorResource(int resId) { this.dividerColor = getResources().getColor(resId); invalidate(); } public int getDividerColor() { return dividerColor; } 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 getShouldExpand() { return shouldExpand; } public boolean isTextAllCaps() { return textAllCaps; } public void setAllCaps(boolean textAllCaps) { this.textAllCaps = textAllCaps; } public void setTextSize(int textSizePx) { this.tabTextSize = textSizePx; updateTabStyles(); } public float getTextSize() { return tabTextSize; } 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()); mCurrentPosition = savedState.currentPosition; requestLayout(); } @Override public Parcelable onSaveInstanceState() { Parcelable superState = super.onSaveInstanceState(); SavedState savedState = new SavedState(superState); savedState.currentPosition = mCurrentPosition; return savedState; } private static final StateListDrawable createStateDrawable() { StateListDrawable stateListDrawable = new StateListDrawable(); ColorDrawable normal = new ColorDrawable(Color.TRANSPARENT); ColorDrawable pressed = new ColorDrawable(Color.parseColor("#66000000")); stateListDrawable.addState(new int[] { android.R.attr.state_pressed, android.R.attr.state_enabled }, pressed); stateListDrawable.addState(new int[] { android.R.attr.state_pressed }, pressed); stateListDrawable.addState(new int[] { android.R.attr.state_enabled }, normal); stateListDrawable.addState(new int[] {}, normal); return stateListDrawable; } 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]; } }; } }