我反编译了一个显示PDF的应用程序，但我的问题是我想实现一个连续的垂直滚动（就像谷歌PDF阅读器一样）......
任何帮助都会得到极大的赞赏......
以下是其PageView的代码 -
public class PageView extends View implements OnGestureListener, OnScaleGestureListener {
protected DocumentActivity actionListener;
protected Bitmap bitmap;
protected int bitmapH;
protected int bitmapW;
protected int canvasH;
protected int canvasW;
protected GestureDetector detector;
protected boolean error;
protected Paint errorPaint;
protected Path errorPath;
protected Paint linkPaint;
protected Link[] links;
protected float maxScale;
protected float minScale;
protected ScaleGestureDetector scaleDetector;
protected int scrollX;
protected int scrollY;
protected Scroller scroller;
protected boolean showLinks;
protected float viewScale;
public PageView(Context var1, AttributeSet var2) {
super(var1, var2);
this.scroller = new Scroller(var1);
this.detector = new GestureDetector(var1, this);
this.scaleDetector = new ScaleGestureDetector(var1, this);
this.viewScale = 1.0F;
this.minScale = 1.0F;
this.maxScale = 2.0F;
this.linkPaint = new Paint();
this.linkPaint.setARGB(32, 0, 0, 255);
this.errorPaint = new Paint();
this.errorPaint.setARGB(255, 255, 80, 80);
this.errorPaint.setStrokeWidth(5.0F);
this.errorPaint.setStyle(Style.STROKE);
this.errorPath = new Path();
this.errorPath.moveTo(-100.0F, -100.0F);
this.errorPath.lineTo(100.0F, 100.0F);
this.errorPath.moveTo(100.0F, -100.0F);
this.errorPath.lineTo(-100.0F, 100.0F);
}
public void goBackward() {
this.scroller.forceFinished(true);
if(this.scrollY <= 0) {
if(this.scrollX <= 0) {
this.actionListener.goBackward();
return;
}
this.scroller.startScroll(this.scrollX, this.scrollY, 9 * -this.canvasW / 10, this.bitmapH - this.canvasH - this.scrollY, 500);
} else {
this.scroller.startScroll(this.scrollX, this.scrollY, 0, 9 * -this.canvasH / 10, 250);
}
this.invalidate();
}
public void goForward() {
this.scroller.forceFinished(true);
if(this.scrollY + this.canvasH >= this.bitmapH) {
if(this.scrollX + this.canvasW >= this.bitmapW) {
this.actionListener.goForward();
return;
}
this.scroller.startScroll(this.scrollX, this.scrollY, 9 * this.canvasW / 10, -this.scrollY, 500);
} else {
this.scroller.startScroll(this.scrollX, this.scrollY, 0, 9 * this.canvasH / 10, 250);
}
this.invalidate();
}
public boolean onDown(MotionEvent var1) {
this.scroller.forceFinished(true);
return true;
}
public void onDraw(Canvas var1) {
if(this.bitmap == null) {
if(this.error) {
var1.translate((float)(this.canvasW / 2), (float)(this.canvasH / 2));
var1.drawPath(this.errorPath, this.errorPaint);
}
} else {
if(this.scroller.computeScrollOffset()) {
this.scrollX = this.scroller.getCurrX();
this.scrollY = this.scroller.getCurrY();
this.invalidate();
}
int var2;
if(this.bitmapW <= this.canvasW) {
this.scrollX = 0;
var2 = (this.canvasW - this.bitmapW) / 2;
} else {
if(this.scrollX < 0) {
this.scrollX = 0;
}
if(this.scrollX > this.bitmapW - this.canvasW) {
this.scrollX = this.bitmapW - this.canvasW;
}
var2 = -this.scrollX;
}
int var3;
if(this.bitmapH <= this.canvasH) {
this.scrollY = 0;
var3 = (this.canvasH - this.bitmapH) / 2;
} else {
if(this.scrollY < 0) {
this.scrollY = 0;
}
if(this.scrollY > this.bitmapH - this.canvasH) {
this.scrollY = this.bitmapH - this.canvasH;
}
var3 = -this.scrollY;
}
var1.translate((float)var2, (float)var3);
var1.scale(this.viewScale, this.viewScale);
var1.drawBitmap(this.bitmap, 0.0F, 0.0F, (Paint)null);
if(this.showLinks && this.links != null) {
Link[] var4 = this.links;
int var5 = var4.length;
for(int var6 = 0; var6 < var5; ++var6) {
Rect var7 = var4[var6].bounds;
var1.drawRect(var7.x0, var7.y0, var7.x1, var7.y1, this.linkPaint);
}
}
}
}
public boolean onFling(MotionEvent var1, MotionEvent var2, float var3, float var4) {
if(this.bitmap != null) {
int var5;
if(this.bitmapW > this.canvasW) {
var5 = this.bitmapW - this.canvasW;
} else {
var5 = 0;
}
int var6;
if(this.bitmapH > this.canvasH) {
var6 = this.bitmapH - this.canvasH;
} else {
var6 = 0;
}
this.scroller.forceFinished(true);
this.scroller.fling(this.scrollX, this.scrollY, (int)(-var3), (int)(-var4), 0, var5, 0, var6);
this.invalidate();
}
return true;
}
public void onLongPress(MotionEvent var1) {
boolean var2;
if(!this.showLinks) {
var2 = true;
} else {
var2 = false;
}
this.showLinks = var2;
this.invalidate();
}
public boolean onScale(ScaleGestureDetector var1) {
if(this.bitmap != null) {
float var2 = var1.getFocusX();
float var3 = var1.getFocusY();
float var4 = var1.getScaleFactor();
float var5 = (var2 + (float)this.scrollX) / this.viewScale;
float var6 = (var3 + (float)this.scrollY) / this.viewScale;
this.viewScale = var4 * this.viewScale;
if(this.viewScale < this.minScale) {
this.viewScale = this.minScale;
}
if(this.viewScale > this.maxScale) {
this.viewScale = this.maxScale;
}
this.bitmapW = (int)((float)this.bitmap.getWidth() * this.viewScale);
this.bitmapH = (int)((float)this.bitmap.getHeight() * this.viewScale);
this.scrollX = (int)(var5 * this.viewScale - var2);
this.scrollY = (int)(var6 * this.viewScale - var3);
this.scroller.forceFinished(true);
this.invalidate();
}
return true;
}
public boolean onScaleBegin(ScaleGestureDetector var1) {
return true;
}
public void onScaleEnd(ScaleGestureDetector var1) {
}
public boolean onScroll(MotionEvent var1, MotionEvent var2, float var3, float var4) {
if(this.bitmap != null) {
this.scrollX += (int)var3;
this.scrollY += (int)var4;
this.scroller.forceFinished(true);
this.invalidate();
}
return true;
}
public void onShowPress(MotionEvent var1) {
}
public boolean onSingleTapUp(MotionEvent var1) {
float var2 = var1.getX();
float var3 = var1.getY();
boolean var4 = this.showLinks;
boolean var5 = false;
if(var4) {
Link[] var8 = this.links;
var5 = false;
if(var8 != null) {
float var9;
if(this.bitmapW <= this.canvasW) {
var9 = (float)((this.bitmapW - this.canvasW) / 2);
} else {
var9 = (float)this.scrollX;
}
float var10;
if(this.bitmapH <= this.canvasH) {
var10 = (float)((this.bitmapH - this.canvasH) / 2);
} else {
var10 = (float)this.scrollY;
}
float var11 = (var2 + var9) / this.viewScale;
float var12 = (var3 + var10) / this.viewScale;
Link[] var13 = this.links;
int var14 = var13.length;
int var15 = 0;
while(true) {
var5 = false;
if(var15 >= var14) {
break;
}
Link var16 = var13[var15];
Rect var17 = var16.bounds;
if(var11 >= var17.x0 && var11 <= var17.x1 && var12 >= var17.y0 && var12 <= var17.y1) {
if(var16.page >= 0) {
this.actionListener.gotoPage(var16.page);
} else if(var16.uri != null) {
this.actionListener.gotoURI(var16.uri);
}
var5 = true;
break;
}
++var15;
}
}
}
if(!var5) {
float var6 = (float)(this.canvasW / 3);
float var7 = var6 * 2.0F;
if(var2 <= var6) {
this.goBackward();
}
if(var2 >= var7) {
this.goForward();
}
if(var2 > var6 && var2 < var7) {
this.actionListener.toggleUI();
}
}
this.invalidate();
return true;
}
public void onSizeChanged(int var1, int var2, int var3, int var4) {
this.canvasW = var1;
this.canvasH = var2;
this.actionListener.onPageViewSizeChanged(var1, var2);
}
public boolean onTouchEvent(MotionEvent var1) {
this.detector.onTouchEvent(var1);
this.scaleDetector.onTouchEvent(var1);
return true;
}
public void setActionListener(DocumentActivity var1) {
this.actionListener = var1;
}
public void setBitmap(Bitmap var1, boolean var2, Link[] var3) {
if(this.bitmap != null) {
this.bitmap.recycle();
}
this.error = false;
this.links = var3;
this.bitmap = var1;
this.bitmapW = (int)((float)this.bitmap.getWidth() * this.viewScale);
this.bitmapH = (int)((float)this.bitmap.getHeight() * this.viewScale);
this.scroller.forceFinished(true);
int var4;
if(var2) {
var4 = this.bitmapW - this.canvasW;
} else {
var4 = 0;
}
this.scrollX = var4;
int var5 = 0;
if(var2) {
var5 = this.bitmapH - this.canvasH;
}
this.scrollY = var5;
this.invalidate();
}
public void setError() {
if(this.bitmap != null) {
this.bitmap.recycle();
}
this.error = true;
this.links = null;
this.bitmap = null;
this.invalidate();
}
}