PDF文档的读取,vudroid(Android)

代码修改自该处(开源 Android pdf 阅读器开发总结)作者分享到Google code的代码,经仔细阅读后整理出读取PDF文档的主要部分(vudroid so库的使用),原作者应该也是在vudroid项目下稍微进行了修改,代码有点乱,所以我整理了下,把关键地方抽了出来,项目中没有提供vudroid so库的源码,所以知道的接口只有那几个,想完整了解vudroid库接口的建议去下载vudroid官方源码,再自行通过ndk编译.(源码下载依然在最后)

import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.RectF;
import android.view.Menu;
import android.view.MotionEvent;
import android.widget.ImageView;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;

import org.vudroid.pdfdroid.codec.*;

public class MainActivity extends Activity {
private PdfContext pdf_conext;
private ImageView view;

private float screen_width = 800;
private float screen_height = 1280;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
view = (ImageView)findViewById(R.id.imageView1);

pdf_conext = new PdfContext();
PdfDocument d = pdf_conext.openDocument("/sdcard/test.pdf");

PdfPage vuPage = d.getPage(1);
RectF rf = new RectF();
rf.bottom = rf.right = (float)1.0;
//参数一二为生成图片的宽高,参数三Rect的top,left,bottom,right为截取部分在该页中的百分比位置
//例如top=0.5,left=0.5,right=1.0,1.0则截取右下角四分之一的部分
Bitmap bitmap = vuPage.renderBitmap((int)screen_width, (int)screen_height, rf);
view.setImageBitmap(bitmap);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}

Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
matrix.set(view.getImageMatrix());
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;

break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);

keepInSight(matrix);

} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);

keepInSight(matrix);
}
}
break;
}
view.setImageMatrix(matrix);
return true;
}

private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}

private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}

private void keepInSight(Matrix m){
float f[] = new float[9];
m.getValues(f);
if(f[0]<1) f[0]=1;
if(f[4]<1) f[4]=1;

if(f[2]>0) f[2]=0;
if(f[5]>0) f[5]=0;

float l = screen_width-screen_width*f[0];
if(f[2]<l) f[2] = l;

float t = screen_height-screen_height*f[0];
if(f[5]<t) f[5] = t;

m.setValues(f);
}
}

源码下载:

http://dl.vmall.com/c0x4dky4py

转载于:https://my.oschina.net/gal/blog/200182