Android 360 degree Joystick
Last Update:2015-11-17
Source: Internet
Author: User
<span id="Label3"></p><p><p>Create a new class. For example, Mysurfaceview</p></p><pre class="brush:java;toolbar:false">package com.example.blt;import android.annotation.suppresslint;import android.content.context; import android.graphics.canvas;import android.graphics.color;import android.graphics.paint; import android.graphics.pixelformat;import android.graphics.porterduff.mode;import Android.util.attributeset;import android.view.motionevent;import android.view.surfaceholder;import android.view.SurfaceView;import android.view.SurfaceHolder.Callback;public class Mysurfaceview extends surfaceview implements callback {private surfaceholder sfh;private canvas canvas;private paint paint;private int coordinate;// Fixed rocker background circle radius private int rockercircler, smallrockercircler;// the x, y coordinates of the joystick and the radius of the joystick private float smallrockercirclex, smallrockercircley;private rudderlistener listener = null; // Event Callback Interface Public mysuRfaceview (context context) {super (Context);} Public mysurfaceview (context context, attributeset as) {super (context, as); This.setkeepscreenon (true); sfh = getholder (); sfh.addcallback (this);p aint = new paint ( );p aint.setcolor (color.green);p aint.setantialias (true);// anti-aliasing setfocusable (true); Setfocusableintouchmode ( true); setzorderontop (true); sfh.setformat (pixelformat.transparent);// Set Background transparency}public void surfacecreated (surfaceholder holder) {// Get control minimum value int little = this.getwidth () < this.getheight () ? this.getwidth (): this.getheight ();// Draw smallrockercirclex = smallrockercircley = coordinate = little /based on screen size 2;// Fixed rocker background circle radius rockercircler = (int) (little * 0.35);// Joystick radius smallrockercircler = (int) (little * 0.15);d Raw ();} /*** * gets the radian between two points */puBlic double getrad (float px1, float py1, float px2, float py2) {// get a distance of two points x float x = px2 - px1;// get two points y distance float y = py1 - py2;// figure out the hypotenuse length float xie = (float) math.sqrt (math.pow (x, 2) + math.pow (y, 2));// obtains the cosine of this angle (through the theorem   in trigonometric functions;: adjacent edge/hypotenuse = Angle Cosine) float cosangle = x / xie;// obtains the Radian float rad = (float) math.acos (cosangle);// by the inverse cosine theorem to its angle. Note: when the position of the touchscreen is Y-coordinate < The y-coordinate of the joystick we want to take the inverse value -0~-180if (py2 < py1) {rad = -rad;} return rad;} @SuppressLint ("clickableviewaccessibility") @Overridepublic boolean ontouchevent (motionevent Event) {if (event.getaction () == motionevent.action_down| | event.getaction () == motionevent.action_move) {// when the touchscreen area is not in the active range if (math.sqrt ( Math.pow ((coordinate - (int) event.getX ()), 2) + math.pow ((coordinate - (int) event.gety ()), 2) >= Rockercircler) {// Get the angle Double temprad = getrad (coordinate, coordinate, which is formed by the rocker and touch point event.getx (), event.gety ());// guarantees the length limit of the inner small circle movement Getxy (coordinate, coordinate, rockercircler, temprad);} else {// if the center point of the ball is smaller than the active area, the smallrockercirclex = (int) event.getx () can be moved as the user touches the Screen. smallrockercircley = (int) event.gety ();}} else if (event.getaction () == motionevent.action_up) {// The position of the joystick to restore the joystick when the key is released is the initial position smallrockercirclex = coordinate; smallrockercircley = coordinate;} Draw ();if (listener != null) {listener.onsteeringwheelchanged ((smallrockercirclex - coordinate)/ rockercircler, (coordinate - smallrockercircley)/ RockerCircleR);} return true;} /** * * @param r * &nbsRotation point of p; circular motion * @param centerX * Rotary point x * @param centery * Rotary point y * @param rad * rotation of radians */public void Getxy (float centerx, float centery, float r, double rad) {// Gets the x-coordinate of the circular motion smallrockercirclex = (float) (r * math.cos (RAD)) + centerx;// Get the y-coordinate of the circular motion smallrockercircley = (float) (r * math.sin (RAD)) + centery;} Public void draw () {try {canvas = sfh.lockcanvas ();// canvas.drawColor ( Color.white) Canvas.drawcolor (color.transparent, mode.clear);// Clear the screen// set Transparency Paint.setcolor ( color.cyan);// Draw joystick Background canVas.drawcircle (coordinate, coordinate, rockercircler, paint);p Aint.setcolor (Color.RED);// Draw Joystick Canvas.drawcircle (smallrockercirclex, smallrockercircley,smallrockercircler, paint);} catch (exception e) {// todo: handle exception} finally {try {if (canvas != null) sfh.unlockcanvasandpost (canvas);} catch (exception e2) {}}}public void surfacechanged (surfaceholder holder, int format, int width,int height) {}public void surfacedestroyed ( Surfaceholder holder) {}// Set Callback interface Public void setrudderlistener (rudderlistener Rockerlistener) {listener = rockerlistener;} Callback Interface public interface rudderlistener {void onsteeringwheelchanged (float cross, float longitudinal);}}</pre><p><p><br></p></p><p><p>In the main form<br></p></p><pre class="brush:java;toolbar:false">package com.example.blt;import android.app.activity;import android.content.intent;import Android.os.bundle;import android.util.log;import android.view.menu;import android.view.menuitem ; Import android.view.view;import android.view.view.onclicklistener;import android.widget.button ; import android.widget.textview;public class controlactivity extends activity {@ Overrideprotected void oncreate (bundle savedinstancestate) {super.oncreate ( savedinstancestate); Setcontentview (r.layout.activity_control); mysurfaceview temp = (mysurfaceview) findviewbyid (r.id.rudder); temp.setRudderListener (new mysurfaceview.rudderlistener () {@Overridepublic void onsteeringwheelchanged (float Cross, float longitudinal) &NBSP;{//&NBSP;TODO&NBSP;AUTO-GENERATED&NBSP;METHOD&NBSP;STUBLOG.V ("change ", " C " + cross + " L " + longitudinal);((TexTView) findviewbyid (r.id.textview2)). setText ("c:" + cross+ "l:" + longitudinal);});( (Button) findviewbyid (r.id.button2)). setonclicklistener (new onclicklistener () {@Overridepublic void onclick (view v) {// todo auto-generated method stub}}); @Overridepublic boolean oncreateoptionsmenu (menu menu) {// inflate the menu ; this adds items to the action bar if it is present.// getmenuinflater (). Inflate (r.menu.control, menu); return false;} @Overridepublic boolean onoptionsitemselected (menuitem item) {// handle action bar item clicks here. The action bar will// automatically handle clicks on the home/up button, so long// as you Specify a parent activity in aNdroidmanifest.xml.int id = item.getitemid ();if (id == r.id.action_settings) {return true;} Return super.onoptionsitemselected (item);}}</pre><p><p>----------------------the main form XML </p> </p><pre class="brush:xml;toolbar:false"><relativelayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http://schemas.android.com/tools" android:layout_width= "match_parent" android:layout_height= "match_parent" android:background= "# FFFFFF " android:paddingbottom=" @dimen/activity_vertical_margin " android:paddingleft= "@dimen/activity_horizontal_margin" android:paddingright= "@dimen/ Activity_horizontal_margin " android:paddingtop=" @dimen/activity_vertical_margin " > <gridlayout android:layout_width = "match_parent" android:layout_height= "match_parent" android:layout_alignparentleft= "true" android:layout_alignparenttop= "true" android:columncount= "3" > <com.example.blt.MySurfaceView android:id= "@+id/rudder" android:layout_width= "150dp" android:layout_height= "150dp" android:layout_column= "0" android:layout_gravity= "left|bottom" /> < Textview android:id= "@+id/textView2" android:layout_column= "1" android:layout_gravity= "left|top" android:text= "TextView" /> < tablelayout android:layout_column= "2" android:layout_gravity= "bottom" android:layout_row= "0" > <TableRow android:id= "@+id/tablerow1" android:layout_width= "WRAP_ Content " android:layout_height= "wrap_content" > < textview android:id= "@+id/axis_x" android:layout_width= "wrap_content" android: layout_height= "wrap_content" android:text= "TextView" /> </TableRow> <TableRow andrOid:id= "@+id/tablerow2" android:layout_width= "wrap_content" android:layout_height= "wrap_content" > <Button android:id= "@+ Id/button2 " android:layout_width= "wrap_content" android:layout_height= "wrap_content" android:text= "automatic" /> < button android:id= "@+id/button3" android:layout_width= "wrap_content" android: layout_height= "wrap_content" android:text= "button" /> </TableRow> <TableRow android:id="@+id/tablerow3" android:layout_width= "wrap_content" android:layout_height= "wrap_content" > <Button android:id= "@+id/ Button1 " android:layout_width= "wrap_content" android:layout_height= "wrap_content" android:text= "button" /≫ <button android:id= "@+id/button4" android:layout_width= "wrap_content" android:layout _height= "wrap_content" android:text= "button" /> </TableRow> <TableRow android:id= "@+Id/tablerow4 " Android:layout_width= "wrap_content" android:layout_height= "wrap_content" > <Button android:id= "@+id/button5" android:layout_width= "wrap_content" android:layout_height= "wrap_content" android:text= "button" /> <button android:id= "@+id/button6" android:layout_width= "wrap_content" android:layout _height= "wrap_content" android:text= "button" /> </tablerow> </ Tablelayout> </gridlayout></relativelayout></pre><p><p>------------------------------apply to custom controls<br></p></p><p><p>This article is from the "stone kee stone" blog, Make sure to keep this source http://nutter.blog.51cto.com/7390238/1713478</p></p><p><p>Android 360 degree Joystick</p></p></span>
