小程序源码 学习相关 DocumentViewer(PDF阅读器).rar

package com.poqop.document; import java.util.HashMap; import java.util.Map; import android.content.Context; import android.graphics.Canvas; import android.graphics.PointF; import android.graphics.RectF; import android.util.FloatMath; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.VelocityTracker; import android.view.View; import android.widget.Scroller; import com.poqop.document.events.ZoomListener; import com.poqop.document.models.CurrentPageModel; import com.poqop.document.models.DecodingProgressModel; import com.poqop.document.models.ZoomModel; import com.poqop.document.multitouch.MultiTouchZoom; /** * 屏幕滚动 * 处理用户翻页操作，比如滑动、点击上下左右键等。 * 此时根据具体的用户操作计算需要显示哪几页，通知BaseViewerActivity去显示这些页 * @author Administrator * */ public class DocumentView extends View implements ZoomListener { final ZoomModel zoomModel; private final CurrentPageModel currentPageModel; DecodeService decodeService; private final HashMap<Integer, Page> pages = new HashMap<Integer, Page>(); private boolean isInitialized = false; private int pageToGoTo; private float lastX; private float lastY; private VelocityTracker velocityTracker; private final Scroller scroller; DecodingProgressModel progressModel; private RectF viewRect; private boolean inZoom; private long lastDownEventTime; private static final int DOUBLE_TAP_TIME = 500; private MultiTouchZoom multiTouchZoom; private static final int MAX_VALUE = 3800; private static final float MULTIPLIER = 400.0f; static final int NONE = 0; //空闲 static final int DRAG = 1; //拖动 static final int ZOOM = 2; //缩放 int mode = NONE; private float oldDist; private PointF midPoint = new PointF(); private boolean isZoom = false; private boolean dblclick = true; public DocumentView(Context context, final ZoomModel zoomModel, DecodingProgressModel progressModel, CurrentPageModel currentPageModel) { super(context); this.zoomModel = zoomModel; this.progressModel = progressModel; this.currentPageModel = currentPageModel; setKeepScreenOn(true); scroller = new Scroller(getContext()); setFocusable(true); setFocusableInTouchMode(true); } public void setDecodeService(DecodeService decodeService) { this.decodeService = decodeService; } private void init() { if (isInitialized) { return; } final int width = decodeService.getEffectivePagesWidth(); //获取试图的宽 final int height = decodeService.getEffectivePagesHeight(); //高 for (int i = 0; i < decodeService.getPageCount(); i++) { pages.put(i, new Page(this, i)); pages.get(i).setAspectRatio(width, height); } isInitialized = true; invalidatePageSizes(); goToPageImpl(pageToGoTo); } private void goToPageImpl(final int toPage) { scrollTo(0, pages.get(toPage).getTop()); } /* * 让视图更新 */ @Override protected void onScrollChanged(int l, int t, int oldl, int oldt) { super.onScrollChanged(l, t, oldl, oldt); // bounds could be not updated post(new Runnable() { public void run() { currentPageModel.setCurrentPageIndex(getCurrentPage()); } }); if (inZoom) { return; } // on scrollChanged can be called from scrollTo just after new layout // applied so we should wait for relayout post(new Runnable() { public void run() { updatePageVisibility(); } }); } private void updatePageVisibility() { for (Page page : pages.values()) { page.updateVisibility(); } } public void commitZoom() { for (Page page : pages.values()) { page.invalidate(); } inZoom = false; } public void showDocument() { // use post to ensure that document view has width and height before // decoding begin post(new Runnable() { public void run() { init(); updatePageVisibility(); } }); } public void goToPage(int toPage) { if (isInitialized) { goToPageImpl(toPage); } else { pageToGoTo = toPage; } } public int getCurrentPage() { for (Map.Entry<Integer, Page> entry : pages.entrySet()) { if (entry.getValue().isVisible()) { return entry.getKey(); } } return 0; } /** * 缩放功能的处理 */ public void zoomChanged(float newZoom, float oldZoom) { inZoom = true; stopScroller(); final float ratio = newZoom / oldZoom; invalidatePageSizes(); scrollTo( (int) ((getScrollX() + getWidth() / 2) * ratio - getWidth() / 2), (int) ((getScrollY() + getHeight() / 2) * ratio - getHeight() / 2)); postInvalidate(); } /** * 触摸屏事件 */ @Override public boolean onTouchEvent(MotionEvent ev) { super.onTouchEvent(ev); if (multiTouchZoom != null) { if (multiTouchZoom.onTouchEvent(ev)) { return true; } if (multiTouchZoom.isResetLastPointAfterZoom()) { setLastPosition(ev); multiTouchZoom.setResetLastPointAfterZoom(false); } } if (velocityTracker == null) { velocityTracker = VelocityTracker.obtain(); //用obtain()函数来获得类的实例，开始计算速度 } velocityTracker.addMovement(ev); //这个方法是将motion event 添加到velocityTracker switch (ev.getAction() & MotionEvent.ACTION_MASK) { case MotionEvent.ACTION_DOWN: mode = DRAG; /* * 双击放大 * 用第一次点击和第二次点击的时间差来判断是否为双击 */ if ((ev.getEventTime() - lastDownEventTime < DOUBLE_TAP_TIME) && dblclick) { setCurrentValue(getmagnifyCurrentValues() - (ev.getX() - lastX)); dblclick=false; mode = DRAG; /* * 双击缩小 */ }else if((ev.getEventTime() - lastDownEventTime < DOUBLE_TAP_TIME) && !dblclick) { setCurrentValue(getReduceCurrentValues() - (ev.getX() - lastX)); dblclick=true; }else{ if (!scroller.isFinished()) { scroller.abortAnimation(); zoomModel.commit(); } else { lastDownEventTime = ev.getEventTime(); } } stopScroller(); setLastPosition(ev); /** * velocityTracker 用来追踪触摸事件（flinging事件和其他手势事件）的速率 * fling(int startX, int startY, int velocityX, int velocityY, int minX, int maxX, int minY, int maxY) * 方法进行控件滚动时各种位置坐标数值的计算 */ case MotionEvent.ACTION_UP: velocityTracker.computeCurrentVelocity(1000); // 初始化速率 scroller.fling(getScrollX(), getScrollY(), (int) -velocityTracker.getXVelocity(), (int) -velocityTracker.getYVelocity(), getLeftLimit(), getRightLimit(), getTopLimit(), getBottomLimit()); velocityTracker.recycle(); //回收 velocityTracker = null; mode = DRAG; break; /** * API原文是 A non-primary pointer has gone down. 翻译过来就是：非第一个点按下 */ case MotionEvent.ACTION_POINTER_DOWN: oldDist = spacing(ev); midPoint(midPoint, ev); isZoom = true; mode = ZOOM; break; case MotionEvent.ACTION_POINTER_UP: mode=DRAG; break; case MotionEvent.ACTION_MOVE: if (mode == DRAG) { scrollBy((int) (lastX - ev.getX()), (int) (lastY - ev.getY())); setLastPosition(ev); break; } else if (mode==ZOOM) { float newDist = spacing(ev); /** * 表示新的距离比两个手指刚触碰的距离大》》》放大 ( +10个像素用来延迟一下放大 */ if (newDist > oldDist + 10) { oldDist = spacing(ev); setCurrentValue(getCurrentValue() - (ev.getX() - lastX)); lastX = ev.getX(); } /** * 表示新的距离比两个手指刚触碰的距离小:>>>>缩小 */ if (newDist + 20 < oldDist) { oldDist = spacing(ev); setCurrentValue(getRedCurrentValues() - (ev.getX() - lastX)); lastX = ev.getX(); } break; }