| /**
* Picture browsing, zooming, dragging, centering automatically
*/
public class touch extends activity implements Ontouchlistener { Matrix matrix = new Matrix ();
Matrix Savedmatrix = new Matrix ();
Displaymetrics DM;
ImageView Imgview;
Bitmap Bitmap; Float minscaler;//Minimum zoom ratio
Static final Float Max_scale = 4f;//maximum Scaling static final int NONE = 0;//initial state
static final int DRAG = 1;//drag
static final int ZOOM = 2;//Scaling
int mode = NONE; PointF prev = new PointF ();
PointF mid = new PointF ();
Float dist = 1f; @Override
public void OnCreate (Bundle savedinstancestate) {
Super.oncreate (savedinstancestate);
Setcontentview (R.layout.scale);
Imgview = (ImageView) Findviewbyid (R.ID.IMAG);//Get control
Bitmap = Bitmapfactory.decoderesource (Getresources (), This.getintent ()
. Getextras (). GetInt ("IMG");//Get Picture resources
Imgview.setimagebitmap (bitmap)//Fill control
Imgview.setontouchlistener (this);/Set Touch screen monitor
DM = new Displaymetrics ();
Getwindowmanager (). Getdefaultdisplay (). Getmetrics (DM);//Get Resolution
Minzoom ();
Center ();
Imgview.setimagematrix (matrix);
} /**
* Touch screen Monitor
*/
public boolean Ontouch (View V, motionevent event) { Switch (event.getaction () & Motionevent.action_mask) {
The main point is pressed
Case Motionevent.action_down:
Savedmatrix.set (matrix);
Prev.set (Event.getx (), event.gety ());
mode = DRAG;
Break
Click on the secondary point
Case Motionevent.action_pointer_down:
Dist = spacing (event);
If the two-point distance is greater than 10, then the multiple point pattern is determined.
if (Spacing (event) > 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 ()-prev.x, Event.gety ()
-PREV.Y);
else if (mode = = ZOOM) {
float newdist = spacing (event);
if (Newdist > 10f) {
Matrix.set (Savedmatrix);
float TScale = newdist/dist;
Matrix.postscale (TScale, TScale, mid.x, MID.Y);
}
}
Break
}
Imgview.setimagematrix (matrix);
Checkview ();
return true;
} /**
* Limit maximum minimum scaling, auto Center
*/
private void Checkview () {
float p[] = new FLOAT[9];
Matrix.getvalues (P);
if (mode = = ZOOM) {
if (P[0] < Minscaler) {
Matrix.setscale (Minscaler, Minscaler);
}
if (P[0] > Max_scale) {
Matrix.set (Savedmatrix);
}
}
Center ();
} /**
* Minimum zoom ratio, maximum is 100%
*/
private void Minzoom () {
Minscaler = Math.min (
(float) dm.widthpixels/(float) bitmap.getwidth (),
(float) dm.heightpixels/(float) bitmap.getheight ());
if (Minscaler < 1.0) {
Matrix.postscale (Minscaler, Minscaler);
}
} private void Center () {
Center (true, true);
} /**
* Horizontal, Vertical Center
*/
protected void Center (Boolean horizontal, Boolean vertical) { Matrix M = new Matrix ();
M.set (matrix);
RECTF rect = new RECTF (0, 0, bitmap.getwidth (), Bitmap.getheight ());
M.maprect (rect); float height = rect.height ();
Float width = rect.width (); Float deltax = 0, DeltaY = 0; if (vertical) {
If the picture is smaller than the screen size, it is centered. Larger than screen, left above left blank to move up, drop down
int screenheight = Dm.heightpixels;
if (height < screenheight) {
DeltaY = (screenheight-height)/2-rect.top;
else if (Rect.top > 0) {
DeltaY =-rect.top;
else if (Rect.bottom < screenheight) {
DeltaY = Imgview.getheight ()-rect.bottom;
}
} if (horizontal) {
int screenwidth = Dm.widthpixels;
if (Width < screenwidth) {
DeltaX = (screenwidth-width)/2-rect.left;
else if (Rect.left > 0) {
DeltaX =-rect.left;
else if (Rect.right < screenwidth) {
DeltaX = Screenwidth-rect.right;
}
}
Matrix.posttranslate (DeltaX, DeltaY);
} /**
* Two-point distance
*/
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);
} /**
* Midpoint of two points
*/
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);
}
} |
