Android multi-touch demo

Mainactivity:

Package Potter. back; </P> <p> Import android. app. activity; </P> <p> public class main extends activity {<br/>/** called when the activity is first created. */<br/> @ override <br/> Public void oncreate (bundle savedinstancestate) {<br/> super. oncreate (savedinstancestate); <br/> // hide the title bar <br/> requestwindowfeature (window. feature_no_title); <br/> // set to full screen <br/> getwindow (). setflags (windowmanager. layoutparams. flag_fullscreen, windowmanager. layoutparams. flag_fullscreen); <br/> // set it to the mtview above <br/> setcontentview (New mysurfaceview (this); <br/>}< br/>}

Surfaceview:

 

Package Potter. back; </P> <p> Import android. content. context; <br/> Import android. graphics. canvas; <br/> Import android. graphics. color; <br/> Import android. graphics. paint; <br/> Import android. view. motionevent; <br/> Import android. view. surfaceholder; <br/> Import android. view. surfaceholder. callback; <br/> Import android. view. surfaceview; </P> <p> public class mysurfaceview extends surfaceview implements call Back {<br/> Private Static final int max_touchpoints = 10; <br/> Private Static final string start_text = "touch the screen to test "; <br/> private paint textpaint = new paint (); <br/> private paint touchpaints [] = new paint [max_touchpoints]; <br/> private int colors [] = new int [max_touchpoints]; <br/> private int width and height; <br/> private float scale = 1.0f; </P> <p> Public mysurfaceview (context) {<br/> supe R (context); <br/> surfaceholder holder = getholder (); <br/> holder. addcallback (this); <br/> setfocusable (true); // ensure that our view can obtain the input focus <br/> setfocusableintouchmode (true ); // ensure that the touch screen event is received <br/> Init (); <br/>}< br/> Public void Init () {<br/> // initialize 10 paint brushes of different colors <br/> textpaint. setcolor (color. white); <br/> colors [0] = color. blue; <br/> colors [1] = color. red; <br/> colors [2] = color. green; <br/> colors [3] = color. yellow; <Br/> colors [4] = color. cyan; <br/> colors [5] = color. magenta; <br/> colors [6] = color. dkgray; <br/> colors [7] = color. white; <br/> colors [8] = color. ltgray; <br/> colors [9] = color. gray; <br/> for (INT I = 0; I <max_touchpoints; I ++) {<br/> touchpaints [I] = new paint (); <br/> touchpaints [I]. setcolor (colors [I]); <br/>}</P> <p> @ override <br/> Public Boolean ontouchevent (motionevent event) {<br/> int pointerc Ount = event. getpointercount (); <br/> If (pointercount> max_touchpoints) {<br/> pointercount = max_touchpoints; <br/>}< br/> canvas c = getholder (). lockcanvas (); <br/> If (C! = NULL) {<br/> C. drawcolor (color. black); <br/> If (event. getaction () = motionevent. action_up) {<br/> // clear the screen when your hand leaves the screen <br/> C. drawcolor (color. black); <br/>}else {<br/> // first draw a cross on the screen and then draw a circle <br/> for (INT I = 0; I <pointercount; I ++) {<br/> // obtain the coordinates of a contact and start to draw <br/> int id = event. getpointerid (I); <br/> int x = (INT) event. getx (I); <br/> int y = (INT) event. gety (I); <br/> drawcrosshairsandtext (X, Y, touchpaints [ID], I, ID, c); <br />}< Br/> for (INT I = 0; I <pointercount; I ++) {<br/> int id = event. getpointerid (I); <br/> int x = (INT) event. getx (I); <br/> int y = (INT) event. gety (I); <br/> drawcircle (X, Y, touchpaints [ID], C ); <br/>}< br/> getholder (). unlockcanvasandpost (c); <br/>}< br/> return true; <br/>}</P> <p> private void drawcrosshairsandtext (int x, int y, paint paint, int PTR, int ID, canvas c) {<br/> C. drawline (0, Y, width, Y, Pai NT); <br/> C. drawline (x, 0, x, height, paint); <br/> int texty = (INT) (15 + 20 * PTR) * scale ); <br/> C. drawtext ("X" + PTR + "=" + X, 10 * scale, texty, textpaint); <br/> C. drawtext ("Y" + PTR + "=" + Y, 70 * scale, texty, textpaint); <br/> C. drawtext ("ID" + PTR + "=" + id, width-55 * scale, texty, textpaint ); <br/>}</P> <p> private void drawcircle (int x, int y, paint, canvas c) {<br/> C. drawci Rcle (X, Y, 40 * scale, paint); <br/>}</P> <p> @ override <br/> Public void surfacechanged (surfaceholder holder, int format, int width, <br/> int height) {<br/> This. width = width; <br/> This. height = height; <br/> If (width> height) {<br/> This. scale = width/480f; <br/>} else {<br/> This. scale = height/480f; <br/>}< br/> textpaint. settextsize (14 * scale); <br/> canvas c = getholder (). lockcanva S (); <br/> If (C! = NULL) {// black background <br/> C. drawcolor (color. black); <br/> float twidth = textpaint. measuretext (start_text); <br/> C. drawtext (start_text, width/2-twidth/2, height/2, textpaint); <br/> getholder (). unlockcanvasandpost (c); <br/>}< br/> @ override <br/> Public void surfacecreated (surfaceholder holder) {<br/> // todo auto-generated method stub </P> <p >}< br/> @ override <br/> Public void surfacedestroyed (surfaceholder holder) {<br/> // todo auto-generated method stub </P> <p >}< br/>