Android implementation slide switch component

Android implementation slide switch component

Because Android does not provide components such as slide switches, we need to implement a custom view component to achieve the slide switch effect.

Here is an example code, which includes three classes: switch component view, status listening interface, MainActivity

Let's take a look at the entire demo:

Let's take a look at the complete code of the view component. The Code has been commented out:

 

Package com. bear. swtichbuttondemo; import java. util. arrayList; import android. content. context; import android. graphics. bitmap; import android. graphics. bitmapFactory; import android. graphics. canvas; import android. graphics. matrix; import android. graphics. paint; import android. graphics. rect; import android. util. attributeSet; import android. view. motionEvent; import android. view. view; import android. view. view. onTouchListener;/*** custom slide switch */public class MySwitchButton extends View implements OnTouchListener {private Bitmap switchOnBkg; // background private Bitmap switchOffBkg when the switch is enabled; // The background private Bitmap slipSwitchButton when the switch is off; // the picture of the sliding switch is private boolean isSlipping = false; // whether the private boolean isSwitchOn is sliding = false; // The status of the current switch. true indicates that the switch is enabled, and flase indicates that the private float previusx is disabled; // The horizontal coordinate xprivate float currentX when the finger is pressed; // The current horizontal coordinate Xprivate ArrayList
 
  
OnSwitchListenerList; // listener list public MySwitchButton (Context context, AttributeSet attrs) {super (context, attrs); init ();} private void init () {this. setOnTouchListener (this); // set the onSwitchListenerList = new ArrayList
  
   
();} Public void setImageResource (int switchBkg, int slipBtn) {switchOnBkg = BitmapFactory. decodeResource (this. getResources (), switchBkg); switchOffBkg = BitmapFactory. decodeResource (this. getResources (), switchBkg); slipSwitchButton = BitmapFactory. decodeResource (this. getResources (), slipBtn);} public void setSwitchState (boolean switchState) {this. isSwitchOn = switchState; this. invalidate ();} public boolean GetSwitchState () {return this. isSwitchOn;} public void setOnSwitchStateListener (OnSwitchListener listener) {onSwitchListenerList. add (listener) ;}@ Overrideprotected void onDraw (Canvas canvas) {super. onDraw (canvas); Matrix matrix = new Matrix (); Paint paint = new Paint (); float leftSlipBtnX; // The left coordinate of the sliding button // the canvas of the background image of the painting switch. drawBitmap (switchOnBkg, matrix, paint); if (isSlipping) {// if sliding if (currentX> switc HOnBkg. getWidth () {leftSlipBtnX = switchOnBkg. getWidth ()-slipSwitchButton. getWidth ();} else {leftSlipBtnX = currentX-slipSwitchButton. getWidth () ;}} else {// if no sliding if (isSwitchOn) {leftSlipBtnX = switchOnBkg. getWidth ()-slipSwitchButton. getWidth () ;}else {leftSlipBtnX = 0 ;}// if the finger slides out of the switch range, it should be processed like this if (leftSlipBtnX <0) {leftSlipBtnX = 0 ;} else if (leftSlipBtnX> switchOnBkg. getWidth ()-slipSwitchBu Tton. getWidth () {leftSlipBtnX = switchOnBkg. getWidth ()-slipSwitchButton. getWidth ();} // draw a toggle canvas on the canvas. drawBitmap (slipSwitchButton, leftSlipBtnX, 0, paint) ;}@ Overrideprotected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) {super. onMeasure (widthMeasureSpec, heightMeasureSpec); setMeasuredDimension (switchOnBkg. getWidth (), switchOnBkg. getHeight () ;}@ Overridepublic boolean onTouch (View V, MotionEvent event) {// obtain the int action = event of the touch action type. getAction (); switch (action) {case MotionEvent. ACTION_MOVE: // if you are currently in the finger-moving state currentX = event. getX (); break; case MotionEvent. ACTION_DOWN: // if the current finger has just pressed the screen status isSlipping = true; break; case MotionEvent. ACTION_UP: // if the current finger has just left the screen status isSlipping = false; boolean previusstate = isSwitchOn; if (event. getX ()> (switchOnBkg. getWidth ()/2) {isSwitchOn = true;} else {isSw ItchOn = false;} // call the interface callback method to notify the listener object if (previusstate! = IsSwitchOn) {if (onSwitchListenerList. size ()> 0) {for (OnSwitchListener listener: onSwitchListenerList) {listener. onSwitched (isSwitchOn) ;}} break; default: break;} this. invalidate (); return true ;}}
  
 

Let's take a look at the code of the switch status listener interface, as shown below:

 

 

package com.bear.swtichbuttondemo;public interface OnSwitchListener {public abstract void onSwitched(boolean isSwitchOn);}

Finally, we will use the code in our Activity. here we need to upload two images to the custom component. Of course, you can also upload two self-prepared images. The Code is as follows:

 

 

Package com. bear. swtichbuttondemo; import android. app. activity; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; import android. widget. toast; public class MainActivity extends Activity {private MySwitchButton mySwitchButton; private Button myBtn; @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanc EState); setContentView (R. layout. activity_main); setupViews ();} private void setupViews () {mySwitchButton = (MySwitchButton) findViewById (R. id. my_switch_button); // upload the image to the custom component mySwitchButton. setImageResource (R. drawable. switch_bkg_switch, R. drawable. switch_btn_slip); myBtn = (Button) findViewById (R. id. button); // set the switch status to listen to mySwitchButton. setOnSwitchStateListener (new OnSwitchListener () {@ Overridepublic void onSw Itched (boolean isSwitchOn) {if (isSwitchOn) {Toast. makeText (MainActivity. this: Toast. LENGTH_SHORT ). show ();} else {Toast. makeText (MainActivity. this: Toast. LENGTH_SHORT ). show () ;}}); myBtn. setOnClickListener (new OnClickListener () {@ Overridepublic void onClick (View v) {boolean isOn = mySwitchButton. getSwitchState (); mySwitchButton. setSwitchState (! IsOn );}});}}