Android Development And Discussion: Place Marker On Static Image Example

Hi Friends,

Once i was working on a project where in app i have to place marker on the static ImageView programmatically onTouchEvent, I Google it but not getting any informative inform from Google then i decide to try this myself, its take my 2 day to complete this task, i know if anyone struck when he/she are at the end of any project that is really frustrating, that's why i am going to share this information with you people hope this will solve your problems:

Example:

Codes:

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<in.androiddevelopmentanddiscussion.markeronimageview.PaintSurface
android:id="@+id/paint_surface"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="50dp" />

<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginBottom="20dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="10dp"
android:gravity="center"
android:text="Where is California (State)"
android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

MainActivity.java

package in.androiddevelopmentanddiscussion.markeronimageview;

import in.androiddevelopmentanddiscussion.drawandcanvasexample.R;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.view.SurfaceHolder;
import android.widget.ImageView;

public class MainActivity extends Activity {

ImageView iv;
PaintSurface mPaintSurface;
final Context context = this;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mPaintSurface = (PaintSurface)findViewById(R.id.paint_surface);

mPaintSurface.setZOrderOnTop(true);
SurfaceHolder sh = mPaintSurface.getHolder();
sh.setFormat(PixelFormat.TRANSLUCENT);

mPaintSurface.setOnTouchListener(mPaintSurface);

}

@Override
protected void onResume() {
super.onResume();
mPaintSurface.resume();
}

@Override
protected void onPause() {
super.onPause();
mPaintSurface.pause();
}

public static void alertMsg(final Context context,String msg){

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
alertDialogBuilder.setTitle("Result");
alertDialogBuilder
.setMessage(msg)
.setCancelable(false)
.setPositiveButton("Ok",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {

Intent intent = ((Activity) context).getIntent();
((Activity) context).overridePendingTransition(0, 0);
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
((Activity) context).finish();
((Activity) context).overridePendingTransition(0, 0);
((Activity) context).startActivity(intent);

}
});

AlertDialog alertDialog = alertDialogBuilder.create();
alertDialog.show();

}

}

PaintSurface.java

package in.androiddevelopmentanddiscussion.markeronimageview;

import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

import android.view.View;

import android.view.View.OnTouchListener;

import in.androiddevelopmentanddiscussion.drawandcanvasexample.R;

import in.androiddevelopmentanddiscussion.markeronimageview.MainActivity;

public class PaintSurface extends SurfaceView implements Runnable, OnTouchListener{

private SurfaceHolder mHolder;

private Thread mThread;

private boolean mFlag = false;

private float mX;

private float mY;

private Paint mPaint,nPaint,lPaint;

Canvas canvas;

float distance;

public PaintSurface(Context context, AttributeSet attrs) {

super(context, attrs);

setBackgroundResource(R.drawable.usa);

mHolder = getHolder();

mPaint = new Paint();

mPaint.setColor(Color.GREEN);

nPaint = new Paint();

nPaint.setColor(Color.RED);

lPaint = new Paint();

lPaint.setColor(Color.BLUE);

}

public void resume(){

// Instantiating the thread

mThread = new Thread(this);

mFlag = true;

mThread.start();

}

public void pause(){

mFlag = false;

}

@Override

public boolean onTouch(View v, MotionEvent event) {

switch(event.getAction()){

case MotionEvent.ACTION_DOWN:

mX = event.getX();

mY = event.getY();

distance = (float) Math.sqrt(Math.pow(101 - mX, 2) + Math.pow(280 - mY, 2));

String msg = "X axis: "+mX+"\nY axis: "+mY+"\nDistance :"+distance;

MainActivity.alertMsg(getContext(),msg);

break;

}

return true;

}

@Override

public void run() {

while(mFlag){

if(!mHolder.getSurface().isValid())

continue;

canvas = mHolder.lockCanvas();

canvas.drawARGB(0, 0, 0, 0);

if(distance<=0){

}else if(distance<50){

Bitmap bmp3 = BitmapFactory.decodeResource(getResources(),R.drawable.green_flag);

canvas.drawBitmap(bmp3, 101- (bmp3.getWidth() / 3), 280- (bmp3.getHeight() / 3), null);

Bitmap bmp2 = BitmapFactory.decodeResource(getResources(),R.drawable.green_flag);

canvas.drawBitmap(bmp2, mX- (bmp2.getWidth() / 3), mY- (bmp2.getHeight() / 3), null);

}else{

Bitmap bmp1 = BitmapFactory.decodeResource(getResources(),R.drawable.green_flag);

canvas.drawBitmap(bmp1, 101- (bmp1.getWidth() / 3), 280- (bmp1.getHeight() / 3), null);

Bitmap bmp = BitmapFactory.decodeResource(getResources(),R.drawable.red_flag);

canvas.drawBitmap(bmp, mX- (bmp.getWidth() / 3), mY- (bmp.getHeight() / 3), null);

canvas.drawLine(101 , 280,mX, mY, lPaint);

}

mHolder.unlockCanvasAndPost(canvas);

}

Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="in.androiddevelopmentanddiscussion.drawandcanvasexample"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="8" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="in.androiddevelopmentanddiscussion.markeronimageview.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

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