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.supermonkey.lifeassistant.view.pager; import android.annotation.SuppressLint; import android.content.Context; 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.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.supermonkey.lifeassistant.R; import java.util.Locale; public class PagerSlidingTabStrip extends HorizontalScrollView { /*************** * ? ******************/ public interface IconTabProvider { /** * ?postion??ID * * @param position * @return */ public int getPageIconResId(int position); } /************************* * ?? *****************************/ // ? // @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; // PagerListener,ViewPager?? private final PageListener pageListener = new PageListener(); // ViewPagerPagerListener public OnPageChangeListener delegatePageListener; // tab private LinearLayout tabsContainer; // ViewPager? private ViewPager pager; // tab? private int tabCount; // tab? private int currentPosition = 0; // tab? private int selectedPosition = 0; // ????? private float currentPositionOffset = 0f; // private Paint rectPaint; // private Paint dividerPaint; // private int indicatorColor = 0xFF666666; // tab 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; // tab? private int tabPadding = 24; // private int dividerWidth = 1; // tab? private int tabTextSize = 12; // tab private int tabTextColor = 0xFF666666; // private int selectedTabTextColor = 0xFF666666; // ? private Typeface tabTypeface = null; // private int tabTypefaceStyle = Typeface.NORMAL; // tab??? private int lastScrollX = 0; // tab private int tabBackgroundResId = R.drawable.pager_background_tab; // ? private Locale locale; // UnderlineIndicator?? private String controlStyle; /********************* * ? ***********************/ 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); // ?View??? setFillViewport(true); // onDraw? setWillNotDraw(false); // tab tabsContainer = new LinearLayout(context); // tab? tabsContainer.setOrientation(LinearLayout.HORIZONTAL); // tabmacth_parent,match_parent tabsContainer.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); // HorizontalScrollViewtab addView(tabsContainer); // ?? DisplayMetrics dm = getResources().getDisplayMetrics(); //?dip?? 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_pstsIndicatorColor, indicatorColor); // ?/ underlineColor = a.getColor(R.styleable.PagerSlidingTabStrip_pstsUnderlineColor, underlineColor); // dividerColor = a.getColor(R.styleable.PagerSlidingTabStrip_pstsDividerColor, dividerColor); // selectedTabTextColor = a.getColor(R.styleable.PagerSlidingTabStrip_pstSelectedTextColor, selectedTabTextColor); // ? indicatorHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsIndicatorHeight, indicatorHeight); // ?/ underlineHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsUnderlineHeight, underlineHeight); // ? dividerPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsDividerPadding, dividerPadding); // ?tab tabPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsTabPaddingLeftRight, tabPadding); // tab tabBackgroundResId = a.getResourceId(R.styleable.PagerSlidingTabStrip_pstsTabBackground, tabBackgroundResId); // ??? shouldExpand = a.getBoolean(R.styleable.PagerSlidingTabStrip_pstsShouldExpand, shouldExpand); // ???? scrollOffset = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsScrollOffset, scrollOffset); // ?? textAllCaps = a.getBoolean(R.styleable.PagerSlidingTabStrip_pstsTextAllCaps, textAllCaps); // ?/? controlStyle = a.getString(R.styleable.PagerSlidingTabStrip_pstsControlStyle); a.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; } } /** * ?ViewPager * * @param pager */ 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(); } /** * pager?? * * @param listener */ public void setOnPageChangeListener(OnPageChangeListener listener) { this.delegatePageListener = listener; } /** * ? */ public void notifyDataSetChanged() { // View tabsContainer.removeAllViews(); // ?pager? tabCount = pager.getAdapter().getCount(); for (int i = 0; i < tabCount; i++) { if (pager.getAdapter() instanceof IconTabProvider) { addIconTab(i, ((IconTabProvider) pager.getAdapter()).getPageIconResId(i)); } else { addTextTab(i, pager.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); } currentPosition = pager.getCurrentItem(); scrollToChild(currentPosition, 0); } }); } /** * tab * * @param position * @param title */ private void addTextTab(final int position, String title) { TextView tab = new TextView(getContext()); tab.setText(title); tab.setGravity(Gravity.CENTER); tab.setSingleLine(); addTab(position, tab); } /** * tab * * @param position * @param resId */ private void addIconTab(final int position, int resId) { ImageButton tab = new ImageButton(getContext()); tab.setImageResource(resId); addTab(position, tab); } /** * tab * * @param position * @param 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, shouldExpand ? expandedTabLayoutParams : defaultTabLayoutParams); } /** * tab? */ private void updateTabStyles() { // tab for (int i = 0; i < tabCount; i++) { // ?? View v = tabsContainer.getChildAt(i); // v.setBackgroundResource(tabBackgroundResId); // ?TextView if (v instanceof TextView) { // TextView TextView tab = (TextView) v; // tab.setTextSize(TypedValue.COMPLEX_UNIT_PX, tabTextSize); // ? tab.setTypeface(tabTypeface, tabTypefaceStyle); // tab.setTextColor(tabTextColor); // setAllCaps() is only available from API 14, so the upper case is made manually if we are on a // pre-ICS-build if (textAllCaps) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { tab.setAllCaps(true); } else { tab.setText(tab.getText().toString().toUpperCase(locale)); } } } } } /** * * * @param position * @param offset */ 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); } } /** * ?onDraw */ @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // isEditMode()? 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); float lineLeft = currentTab.getLeft(); float lineRight = currentTab.getRight(); // if there is an offset, start interpolating left and right coordinates between current and next tab // currentPosition0 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); } canvas.drawRect(lineLeft, height - indicatorHeight, lineRight, height, rectPaint); // draw underline rectPaint.setColor(underlineColor); // /? // /* * canvas.drawRect(0, height - underlineHeight, * tabsContainer.getWidth(), height, rectPaint); */ // canvas.drawRect(0, 0, tabsContainer.getWidth(), underlineHeight, 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 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) { selectedPosition = position; updateTabStyles(); if (delegatePageListener != null) { delegatePageListener.onPageSelected(position); } } } /** * * * @param indicatorColor */ public void setIndicatorColor(int indicatorColor) { this.indicatorColor = indicatorColor; invalidate(); } /** * ?ID * * @param resId */ public void setIndicatorColorResource(int resId) { this.indicatorColor = getResources().getColor(resId); invalidate(); } /** * ? * * @return */ public int getIndicatorColor() { return this.indicatorColor; } /** * * * @param indicatorLineHeightPx */ public void setIndicatorHeight(int indicatorLineHeightPx) { this.indicatorHeight = indicatorLineHeightPx; invalidate(); } /** * ? * * @return */ public int getIndicatorHeight() { return indicatorHeight; } /** * / * * @param underlineColor */ public void setUnderlineColor(int underlineColor) { this.underlineColor = underlineColor; invalidate(); } /** * /?ID * * @param resId */ public void setUnderlineColorResource(int resId) { this.underlineColor = getResources().getColor(resId); invalidate(); } /** * ? * * @return */ public int getUnderlineColor() { return underlineColor; } /** * * * @param dividerColor */ public void setDividerColor(int dividerColor) { this.dividerColor = dividerColor; invalidate(); } /** * ?ID * * @param resId */ public void setDividerColorResource(int resId) { this.dividerColor = getResources().getColor(resId); invalidate(); } /** * ? * * @return */ public int getDividerColor() { return dividerColor; } /** * / * * @param underlineHeightPx */ public void setUnderlineHeight(int underlineHeightPx) { this.underlineHeight = underlineHeightPx; invalidate(); } /** * ?/ * * @return */ public int getUnderlineHeight() { return underlineHeight; } /** * ? * * @param dividerPaddingPx */ public void setDividerPadding(int dividerPaddingPx) { this.dividerPadding = dividerPaddingPx; invalidate(); } /** * ?? * * @return */ public int getDividerPadding() { return dividerPadding; } /** * ??? * * @param scrollOffsetPx */ public void setScrollOffset(int scrollOffsetPx) { this.scrollOffset = scrollOffsetPx; invalidate(); } /** * ???? * * @return */ public int getScrollOffset() { return scrollOffset; } /** * ??truefalse? * * @param shouldExpand */ public void setShouldExpand(boolean shouldExpand) { this.shouldExpand = shouldExpand; requestLayout(); } /** * ? * * @return */ public boolean getShouldExpand() { return shouldExpand; } /** * ?? * * @return */ public boolean isTextAllCaps() { return textAllCaps; } /** * * * @param textAllCaps */ public void setAllCaps(boolean textAllCaps) { this.textAllCaps = textAllCaps; } /** * ? * * @param textSizePx */ public void setTextSize(int textSizePx) { this.tabTextSize = textSizePx; updateTabStyles(); } /** * ?? * * @return */ public int getTextSize() { return tabTextSize; } /** * * * @param textColor */ public void setTextColor(int textColor) { this.tabTextColor = textColor; updateTabStyles(); } /** * ?ID * * @param resId */ public void setTextColorResource(int resId) { this.tabTextColor = getResources().getColor(resId); updateTabStyles(); } /** * ? * * @return */ public int getTextColor() { return tabTextColor; } public void setSelectedTextColor(int textColor) { this.selectedTabTextColor = textColor; updateTabStyles(); } public void setSelectedTextColorResource(int resId) { this.selectedTabTextColor = getResources().getColor(resId); updateTabStyles(); } public int getSelectedTextColor() { return selectedTabTextColor; } /** * TypeFace * * @param typeface * @param style */ public void setTypeface(Typeface typeface, int style) { this.tabTypeface = typeface; this.tabTypefaceStyle = style; updateTabStyles(); } /** * ?ID * * @param resId */ public void setTabBackground(int resId) { this.tabBackgroundResId = resId; } /** * ??ID * * @return */ public int getTabBackground() { return tabBackgroundResId; } /** * ?? */ public void setTabPaddingLeftRight(int paddingPx) { this.tabPadding = paddingPx; updateTabStyles(); } /** * ??? * * @return */ public int getTabPaddingLeftRight() { return tabPadding; } /** * ?? * * @return */ public String getUnderLineLocation() { return controlStyle; } /** * ? * * @param controlstyle */ public void setUnderLineLocation(String controlstyle) { this.controlStyle = controlstyle; } @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]; } }; } }