Android进阶篇-时间滑动控件
仿Iphone时间选择滑动控件：
WheelView.java:
/** * @author Administrator * * 时间滑动滚轮 */ public class WheelView extends View{ /** 手势监听控件 **/ private GestureDetector gestureDetector; /** 滑动管理类 **/ private Scroller scroller; /** 适配器 **/ private WheelAdapter adapter; private StaticLayout itemsLayout; private StaticLayout labelLayout; private StaticLayout valueLayout; /** 滑动偏移量 **/ private int scrollingOffset; /** 当前的Item **/ private int currentItem = 0; /** 默认的可见的Item个数 **/ private static final int DEF_VISIBLE_ITEMS = 5; private int visibleItems = DEF_VISIBLE_ITEMS; /** 标签 **/ private String label; /** 图片 **/ private Drawable centerDrawable; /** 是否回收 **/ private boolean isCyclic = false; private List<OnWheelChangedListener> changingListeners = new LinkedList<OnWheelChangedListener>(); private List<OnWheelScrollListener> scrollingListeners = new LinkedList<OnWheelScrollListener>(); /** 滑动的频率 **/ private static final int SCROLLING_DURATION = 400; /** 文字大小 */ private static final int TEXT_SIZE = 24; private TextPaint itemsPaint; private TextPaint valuePaint; private GradientDrawable topShadow; private GradientDrawable bottomShadow; private static final int[] SHADOWS_COLORS = new int[] { 0xFF111111, 0x00AAAAAA, 0x00AAAAAA }; private static final int ITEM_OFFSET = TEXT_SIZE / 5; private static final int ADDITIONAL_ITEM_HEIGHT = 15; private static final int LABEL_OFFSET = 8; private static final int ADDITIONAL_ITEMS_SPACE = 10; private static final int PADDING = 10; private int itemHeight = 0; private int itemsWidth = 0; private int labelWidth = 0; private int lastScrollY; // Messages private final int MESSAGE_SCROLL = 0; private final int MESSAGE_JUSTIFY = 1; private boolean isScrollingPerformed; private static final int MIN_DELTA_FOR_SCROLLING = 1; private static final int ITEMS_TEXT_COLOR = 0xFF000000; private static final int VALUE_TEXT_COLOR = 0xF0000000; public WheelView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); // TODO Auto-generated constructor stub init(); } public WheelView(Context context, AttributeSet attrs) { super(context, attrs); // TODO Auto-generated constructor stub init(); } public WheelView(Context context) { super(context); // TODO Auto-generated constructor stub init(); } private void init() { gestureDetector = new GestureDetector(getContext(), gestureListener); gestureDetector.setIsLongpressEnabled(false); scroller = new Scroller(getContext()); } public WheelAdapter getAdapter() { return adapter; } public void setAdapter(WheelAdapter adapter) { this.adapter = adapter; invalidateLayouts(); invalidate(); } /** * @param interpolator 动画插补器 */ public void setInterpolator(Interpolator interpolator){ // 立即停止滑动 scroller.forceFinished(true); scroller = new Scroller(getContext(),interpolator); } /** * 初始布局 */ private void invalidateLayouts() { itemsLayout = null; valueLayout = null; scrollingOffset = 0; } public int getVisiableItems() { return visibleItems; } public void setVisiableItems(int count) { visibleItems = count; invalidate(); } public String getLabel() { return label; } public void setLabel(String newLabel) { if(label == null || !label.equals(newLabel)) { label = newLabel; labelLayout = null; invalidate(); } } public void addChangingListener(OnWheelChangedListener listener){ changingListeners.add(listener); } public void removeChangingListener(OnWheelChangedListener listener) { changingListeners.remove(listener); } /** * 更新监听 * * @param oldValue * @param newValue */ protected void notifyChangingListeners(int oldValue, int newValue) { for (OnWheelChangedListener listener : changingListeners) { listener.onChanged(this, oldValue, newValue); } } public void addScrollingListener(OnWheelScrollListener listener) { scrollingListeners.add(listener); } public void removeScrollingListener(OnWheelScrollListener listener) { scrollingListeners.remove(listener); } /** * 更新滑动监听 */ protected void notifyScrollingListenersAboutStart() { for (OnWheelScrollListener listener : scrollingListeners) { listener.onScrollingStarted(this); } } protected void notifyScrollingListenersAboutEnd() { for (OnWheelScrollListener listener : scrollingListeners) { listener.onScrollingFinished(this); } } public int getCurrentItem() { return currentItem; } /** * 设置当前的Item * * @param index 下标 * @param animated 是否开启动画效果 */ public void setCurrentItem(int index,boolean animated) { if(adapter == null || (adapter != null && adapter.getItemCount() == 0)) { return; } if(index < 0 || index >= adapter.getItemCount()) { if (isCyclic) { while (index < 0) { index += adapter.getItemCount(); } index %= adapter.getItemCount(); } else{ return; } } if (index != currentItem) { if (animated) { scroll(index - currentItem, SCROLLING_DURATION); } else { invalidateLayouts(); int old = currentItem; currentItem = index; notifyChangingListeners(old, currentItem); invalidate(); } } } public void setCurrentItem(int index) { setCurrentItem(index, false); } public boolean isCyclic() { return isCyclic; } public void setCyclic(boolean isCyclis) { this.isCyclic = isCyclis; invalidateLayouts(); invalidate(); } private void initResourcesIfNecessary() { if(itemsPaint == null) { /** 设置粗体 抗锯齿 **/ itemsPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.FAKE_BOLD_TEXT_FLAG); itemsPaint.setTextSize(TEXT_SIZE); } if(valuePaint == null) { /** 设置粗体 抗锯齿 递色 **/ valuePaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.FAKE_BOLD_TEXT_FLAG | Paint.DITHER_FLAG); valuePaint.setTextSize(TEXT_SIZE); /** 绘制阴影 **/ valuePaint.setShadowLayer(0.1f, 0, 0.1f, 0xFFC0C0C0); } if (centerDrawable == null) { centerDrawable = getContext().getResources().getDrawable(R.drawable.wheel_val); } if (topShadow == null) { topShadow = new GradientDrawable(Orientation.TOP_BOTTOM, SHADOWS_COLORS); } if (bottomShadow == null) { bottomShadow = new GradientDrawable(Orientation.BOTTOM_TOP, SHADOWS_COLORS); } setBackgroundResource(R.drawable.wheel_bg); } /** * 计算布局的高度 * * @param layout * @return */ private int getDesiredHeight(Layout layout) { if(layout == null) { return 0; } int desired = getItemHeight() * visibleItems - ITEM_OFFSET * 2 - ADDITIONAL_ITEM_HEIGHT; // Check against our minimum height desired = Math.max(desired, getSuggestedMinimumHeight()); return desired; } /** * 设置TextItem * * @param index * @return */ private String getTextItem(int index) { if (adapter == null || adapter.getItemCount() == 0) { return null; } int count = adapter.getItemCount(); if ((index < 0 || index >= count) && !isCyclic) { return null; } else { while (index < 0) { index = count + index; } } index %= count; return (String) adapter.getItem(index); } private String buildText(boolean useCurrentValue) { StringBuilder itemsText = new StringBuilder(); int addItems = visibleItems / 2 + 1; for (int i = currentItem - addItems; i <= currentItem + addItems; i++) { if (useCurrentValue || i != currentItem) { String text = getTextItem(i); if (text != null) { itemsText.append(text); } } if (i < currentItem + addItems) { itemsText.append(" "); } } return itemsText.toString(); } private int getMaxTextLength() { WheelAdapter adapter = getAdapter(); if (adapter == null) { return 0; } int adapterLength = adapter.getMaxinumLength(); if (adapterLength > 0) { return adapterLength; } String maxText = null; int addItems = visibleItems / 2; for (int i = Math.max(currentItem - addItems, 0); i < Math.min(currentItem + visibleItems, adapter.getItemCount()); i++) { String text = (String) adapter.getItem(i); if (text != null && (maxText == null || maxText.length() < text.length())) { maxText = text; } } return maxText != null ? maxText.length() : 0; } private int getItemHeight() { if (itemHeight != 0) { return itemHeight; } else if (itemsLayout != null && itemsLayout.getLineCount() > 2) { itemHeight = itemsLayout.getLineTop(2) - itemsLayout.getLineTop(1); return itemHeight; } return getHeight() / visibleItems; } private int calculateLayoutWidth(int widthSize, int mode) { initResourcesIfNecessary(); int width = widthSize; int maxLength = getMaxTextLength(); if (maxLength > 0) { float textWidth = FloatMath.ceil(Layout.getDesiredWidth("0", itemsPaint)); itemsWidth = (int) (maxLength * textWidth); } else { itemsWidth = 0; } itemsWidth += ADDITIONAL_ITEMS_SPACE; // make it some more labelWidth = 0; if (label != null && label.length() > 0) { labelWidth = (int) FloatMath.ceil(Layout.getDesiredWidth(label, valuePaint)); } boolean recalculate = false; if (mode == MeasureSpec.EXACTLY) { width = widthSize; recalculate = true; } else { width = itemsWidth + labelWidth + 2 * PADDING; if (labelWidth > 0) { width += LABEL_OFFSET; } // Check against our minimum width width = Math.max(width, getSuggestedMinimumWidth()); if (mode == MeasureSpec.AT_MOST && widthSize < width) { width = widthSize; recalculate = true; } } if (recalculate) { // recalculate width int pureWidth = width - LABEL_OFFSET - 2 * PADDING; if (pureWidth <= 0) { itemsWidth = labelWidth = 0; } if (labelWidth > 0) { double newWidthItems = (double) itemsWidth * pureWidth / (itemsWidth + labelWidth); itemsWidth = (int) newWidthItems; labelWidth = pureWidth - itemsWidth; } else { itemsWidth = pureWidth + LABEL_OFFSET; // no label } } if (itemsWidth > 0) { createLayouts(itemsWidth, labelWidth); } return width; } private void createLayouts(int widthItems, int widthLabel) { if (itemsLayout == null || itemsLayout.getWidth() > widthItems) { itemsLayout = new StaticLayout(buildText(isScrollingPerformed), itemsPaint, widthItems, widthLabel > 0 ? Layout.Alignment.ALIGN_OPPOSITE : Layout.Alignment.ALIGN_CENTER, 1, ADDITIONAL_ITEM_HEIGHT, false); } else { itemsLayout.increaseWidthTo(widthItems); } if (!isScrollingPerformed && (valueLayout == null || valueLayout.getWidth() > widthItems)) { String text = (String) (getAdapter() != null ? getAdapter().getItem(currentItem) : null); valueLayout = new StaticLayout(text != null ? text : "", valuePaint, widthItems, widthLabel > 0 ? Layout.Alignment.ALIGN_OPPOSITE : Layout.Alignment.ALIGN_CENTER, 1, ADDITIONAL_ITEM_HEIGHT, false); } else if (isScrollingPerformed) { valueLayout = null; } else { valueLayout.increaseWidthTo(widthItems); } if (widthLabel > 0) { if (labelLayout == null || labelLayout.getWidth() > widthLabel) { labelLayout = new StaticLayout(label, valuePaint, widthLabel, Layout.Alignment.ALIGN_NORMAL, 1, ADDITIONAL_ITEM_HEIGHT, false); } else { labelLayout.increaseWidthTo(widthLabel); } } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int widthMode = MeasureSpec.getMode(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); int widthSize = MeasureSpec.getSize(widthMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec); int width = calculateLayoutWidth(widthSize, widthMode); int height; if (heightMode == MeasureSpec.EXACTLY) { height = heightSize; } else { height = getDesiredHeight(itemsLayout); if (heightMode == MeasureSpec.AT_MOST) { height = Math.min(height, heightSize); } } setMeasuredDimension(width, height); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (itemsLayout == null) { if (itemsWidth == 0) { calculateLayoutWidth(getWidth(), MeasureSpec.EXACTLY); } else { createLayouts(itemsWidth, labelWidth); } } if (itemsWidth > 0) { canvas.save(); // Skip padding space and hide a part of top and bottom items canvas.translate(PADDING, -ITEM_OFFSET); drawItems(canvas); drawValue(canvas); canvas.restore(); } drawCenterRect(canvas); drawShadows(canvas); } private void drawShadows(Canvas canvas) { topShadow.setBounds(0, 0, getWidth(), getHeight() / visibleItems); topShadow.draw(canvas); bottomShadow.setBounds(0, getHeight() - getHeight() / visibleItems, getWidth(), getHeight()); bottomShadow.draw(canvas); } private void drawValue(Canvas canvas) { valuePaint.setColor(VALUE_TEXT_COLOR); valuePaint.drawableState = getDrawableState(); Rect bounds = new Rect(); itemsLayout.getLineBounds(visibleItems / 2, bounds); // draw label if (labelLayout != null) { canvas.save(); canvas.translate(itemsLayout.getWidth() + LABEL_OFFSET, bounds.top); labelLayout.draw(canvas); canvas.restore(); } // draw current value if (valueLayout != null) { canvas.save(); canvas.translate(0, bounds.top + scrollingOffset); valueLayout.draw(canvas); canvas.restore(); } } private void drawItems(Canvas canvas) { canvas.save(); int top = itemsLayout.getLineTop(1); canvas.translate(0, - top + scrollingOffset); itemsPaint.setColor(ITEMS_TEXT_COLOR); itemsPaint.drawableState = getDrawableState(); itemsLayout.draw(canvas); canvas.restore(); } private void drawCenterRect(Canvas canvas) { int center = getHeight() / 2; int offset = getItemHeight() / 2; centerDrawable.setBounds(0, center - offset, getWidth(), center + offset); centerDrawable.draw(canvas); } /** * 拦截onTouchEvent */ @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub WheelAdapter adapter = getAdapter(); if (adapter == null) { return true; } if (!gestureDetector.onTouchEvent(event) && event.getAction() == MotionEvent.ACTION_UP) { justify(); } return true; } /** * 滑动 * * @param delta */ private void doScroll(int delta) { scrollingOffset += delta; int count = scrollingOffset / getItemHeight(); int pos = currentItem - count; if (isCyclic && adapter.getItemCount() > 0) { // fix position by rotating while (pos < 0) { pos += adapter.getItemCount(); } pos %= adapter.getItemCount(); } else if (isScrollingPerformed) { // if (pos < 0) { count = currentItem; pos = 0; } else if (pos >= adapter.getItemCount()) { count = currentItem - adapter.getItemCount() + 1; pos = adapter.getItemCount() - 1; } } else { // fix position pos = Math.max(pos, 0); pos = Math.min(pos, adapter.getItemCount() - 1); } int offset = scrollingOffset; if (pos != currentItem) { setCurrentItem(pos, false); } else { invalidate(); } // update offset scrollingOffset = offset - count * getItemHeight(); if (scrollingOffset > getHeight()) { scrollingOffset = scrollingOffset % getHeight() + getHeight(); } } /** * 手势监听事件 */ private SimpleOnGestureListener gestureListener = new SimpleOnGestureListener(){ @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { // TODO Auto-generated method stub startScrolling(); doScroll((int)-distanceY); return true; } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { // TODO Auto-generated method stub lastScrollY = currentItem * getItemHeight() + scrollingOffset; int maxY = isCyclic ? 0x7FFFFFFF : adapter.getItemCount() * getItemHeight(); int minY = isCyclic ? -maxY : 0; scroller.fling(0, lastScrollY, 0, (int) -velocityY / 2, 0, 0, minY, maxY); setNextMessage(MESSAGE_SCROLL); return true; } @Override public boolean onDown(MotionEvent e) { // TODO Auto-generated method stub if (isScrollingPerformed) { scroller.forceFinished(true); clearMessages(); return true; } return false; } }; private void setNextMessage(int message) { clearMessages(); animationHandler.sendEmptyMessage(message); } /** * 清空Message */ private void clearMessages() { animationHandler.removeMessages(MESSAGE_SCROLL); animationHandler.removeMessages(MESSAGE_JUSTIFY); } /** * 动画Handler */ private Handler animationHandler = new Handler() { public void handleMessage(Message msg) { scroller.computeScrollOffset(); int currY = scroller.getCurrY(); int delta = lastScrollY - currY; lastScrollY = currY; if (delta != 0) { doScroll(delta); } if (Math.abs(currY - scroller.getFinalY()) < MIN_DELTA_FOR_SCROLLING) { currY = scroller.getFinalY(); scroller.forceFinished(true); } if (!scroller.isFinished()) { animationHandler.sendEmptyMessage(msg.what); } else if (msg.what == MESSAGE_SCROLL) { justify(); } else { finishScrolling(); } } }; private void justify() { if (adapter == null) { return; } lastScrollY = 0; int offset = scrollingOffset; int itemHeight = getItemHeight(); boolean needToIncrease = offset > 0 ? currentItem < adapter.getItemCount() : currentItem > 0; if ((isCyclic || needToIncrease) && Math.abs((float) offset) > (float) itemHeight / 2) { if (offset < 0) offset += itemHeight + MIN_DELTA_FOR_SCROLLING; else offset -= itemHeight + MIN_DELTA_FOR_SCROLLING; } if (Math.abs(offset) > MIN_DELTA_FOR_SCROLLING) { scroller.startScroll(0, 0, 0, offset, SCROLLING_DURATION); setNextMessage(MESSAGE_JUSTIFY); } else { finishScrolling(); } } /** * 开始滑动 */ private void startScrolling() { if (!isScrollingPerformed) { isScrollingPerformed = true; notifyScrollingListenersAboutStart(); } } /** * 结束滑动 */ void finishScrolling() { if (isScrollingPerformed) { notifyScrollingListenersAboutEnd(); isScrollingPerformed = false; } invalidateLayouts(); invalidate(); } /** * 滑动这滚轮 * * @param itemsToScroll * @param time */ public void scroll(int itemsToScroll, int time) { scroller.forceFinished(true); lastScrollY = scrollingOffset; int offset = itemsToScroll * getItemHeight(); scroller.startScroll(0, lastScrollY, 0, offset - lastScrollY, time); setNextMessage(MESSAGE_SCROLL); startScrolling(); } }
WheelAdapter.java:
public interface WheelAdapter { /** 获取Size **/ public int getItemCount(); /** 获取Item对象 **/ public Object getItem(int index); /** 获取每个Item的最大长度 用来设置画的时候的宽度 **/ public int getMaxinumLength(); }
OnWheelScrollListener.java:
public interface OnWheelScrollListener { void onScrollingStarted(WheelView wheel); void onScrollingFinished(WheelView wheel); }
OnWheelChangedListener.java:
public interface OnWheelChangedListener { void onChanged(WheelView wheel, int oldValue, int newValue); }
适配器NumberWheelAdapter.java:
public class NumberWheelAdapter implements WheelAdapter{ /** The default min value */ public static final int DEFAULT_MAX_VALUE = 9; /** The default max value */ private static final int DEFAULT_MIN_VALUE = 0; // Values private int minValue; private int maxValue; // format private String format; public NumberWheelAdapter() { this(DEFAULT_MIN_VALUE, DEFAULT_MAX_VALUE); } public NumberWheelAdapter(int minValue, int maxValue) { this(minValue, maxValue, null); } public NumberWheelAdapter(int minValue, int maxValue, String format) { this.minValue = minValue; this.maxValue = maxValue; this.format = format; } @Override public int getItemCount() { // TODO Auto-generated method stub return maxValue - minValue + 1; } @Override public Object getItem(int index) { // TODO Auto-generated method stub if (index >= 0 && index < getItemCount()) { int value = minValue + index; return format != null ? String.format(format, value) : Integer.toString(value); } return null; } @Override public int getMaxinumLength() { // TODO Auto-generated method stub int max = Math.max(Math.abs(maxValue), Math.abs(minValue)); int maxLen = Integer.toString(max).length(); if (minValue < 0) { maxLen++; } return maxLen; } }
activity调用:
mMonthWheel = (WheelView) findViewById(R.id.hour); mDayWheel = (WheelView) findViewById(R.id.mins); mMonthWheel.setAdapter(new NumberWheelAdapter(1, 12)); mMonthWheel.setLabel("月"); mDayWheel.setAdapter(new NumberWheelAdapter(1, 31)); mDayWheel.setLabel("日"); mDayWheel.setCyclic(true);