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How to clear image to

We create an application in which people can draw a sketch and save it in the gallery. I did it and it works great. What I would like to do is take an image from the Gallery and be able to draw it. I was able to open the gallery to select an image, but I could not figure out how to paste this image onto the canvas, and then draw

but the problem is that it opens the gallery ... but when I click on any pic to open it, it just returns to the application, but not with the image, without the picture (my screen remains the same as before, there is no new pictures) ... so what's the problem?

My Mainactivity Class ---

package com.example.drawingfun;


import java.io.File;
import java.io.FileNotFoundException;
import java.io.InputStream;

import java.util.UUID;


import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;

import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ImageButton;

import android.widget.LinearLayout;
import android.widget.Toast;

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;


import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;


import android.view.View.OnClickListener;





public class MainActivity extends Activity implements OnClickListener {

    private DrawingView drawView;
    private ImageButton currPaint,drawBtn,eraseBtn, newBtn,saveBtn,gal;
    private float smallBrush, mediumBrush,largeBrush;

    int GALLERY_INTENT_CALLED = 3; // has to be a unique request code
    Drawable image;



    @Override
    protected void onCreate(Bundle savedInstanceState) {




        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        drawView = (DrawingView)findViewById(R.id.drawing);
        LinearLayout paintLayout = (LinearLayout)findViewById(R.id.paint_colors);
        currPaint = (ImageButton)paintLayout.getChildAt(0);
        currPaint.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));
        smallBrush = getResources().getInteger(R.integer.small_size);
        mediumBrush = getResources().getInteger(R.integer.medium_size);
        largeBrush = getResources().getInteger(R.integer.large_size);




        drawBtn = (ImageButton)findViewById(R.id.draw_btn);
        drawBtn.setOnClickListener(this);


        drawView.setBrushSize(mediumBrush);
        eraseBtn = (ImageButton)findViewById(R.id.erase_btn);
        eraseBtn.setOnClickListener(this);
        newBtn = (ImageButton)findViewById(R.id.new_btn);
        newBtn.setOnClickListener(this);
        saveBtn = (ImageButton)findViewById(R.id.save_btn);
        saveBtn.setOnClickListener(this);
        gal = (ImageButton)findViewById(R.id.GalleryButton);
        gal.setOnClickListener(this);




    }



    public void paintClicked(View view){



        drawView.setErase(false);
        drawView.setBrushSize(drawView.getLastBrushSize());
        //use chosen color

        if(view!=currPaint){
            //update color
            ImageButton imgView = (ImageButton)view;
            String color = view.getTag().toString();
            drawView.setColor(color);
            imgView.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));
            currPaint.setImageDrawable(getResources().getDrawable(R.drawable.paint));
            currPaint=(ImageButton)view;
            }







    }




    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }











    @Override
    public void onClick(View view){
        //respond to clicks
        if(view.getId()==R.id.draw_btn){
            //draw button clicked

            final Dialog brushDialog = new Dialog(this);
            brushDialog.setTitle("Brush size:");
            brushDialog.setContentView(R.layout.brush_chooser);


            ImageButton smallBtn = (ImageButton)brushDialog.findViewById(R.id.small_brush);
            smallBtn.setOnClickListener(new OnClickListener(){
                @Override
                public void onClick(View v) {
                    drawView.setErase(false);
                    drawView.setBrushSize(smallBrush);
                    drawView.setLastBrushSize(smallBrush);

                    brushDialog.dismiss();
                }
            });

            ImageButton mediumBtn = (ImageButton)brushDialog.findViewById(R.id.medium_brush);
            mediumBtn.setOnClickListener(new OnClickListener(){
                @Override
                public void onClick(View v) {
                    drawView.setErase(false);
                    drawView.setBrushSize(mediumBrush);
                    drawView.setLastBrushSize(mediumBrush);


                    brushDialog.dismiss();


                }
            });
            ImageButton largeBtn = (ImageButton)brushDialog.findViewById(R.id.large_brush);
            largeBtn.setOnClickListener(new OnClickListener(){
                @Override
                public void onClick(View v) {
                    drawView.setErase(false);
                    drawView.setBrushSize(largeBrush);
                    drawView.setLastBrushSize(largeBrush);

                    brushDialog.dismiss();
                }
            });






            brushDialog.show();






        }

























        else if(view.getId()==R.id.erase_btn){
            //switch to erase - choose size
            final Dialog brushDialog = new Dialog(this);
            brushDialog.setTitle("Eraser size:");
            brushDialog.setContentView(R.layout.brush_chooser);

            ImageButton smallBtn = (ImageButton)brushDialog.findViewById(R.id.small_brush);
            smallBtn.setOnClickListener(new OnClickListener(){
                @Override
                public void onClick(View v) {
                    drawView.setErase(true);
                    drawView.setBrushSize(smallBrush);
                    brushDialog.dismiss();
                }
            });
            ImageButton mediumBtn = (ImageButton)brushDialog.findViewById(R.id.medium_brush);
            mediumBtn.setOnClickListener(new OnClickListener(){
                @Override
                public void onClick(View v) {
                    drawView.setErase(true);
                    drawView.setBrushSize(mediumBrush);
                    brushDialog.dismiss();
                }
            });
            ImageButton largeBtn = (ImageButton)brushDialog.findViewById(R.id.large_brush);
            largeBtn.setOnClickListener(new OnClickListener(){
                @Override
                public void onClick(View v) {
                    drawView.setErase(true);
                    drawView.setBrushSize(largeBrush);
                    brushDialog.dismiss();
                }
            });
            brushDialog.show();
        }

        else if(view.getId()==R.id.new_btn){
            //new button

            AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
            newDialog.setTitle("New drawing");
            newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
            newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    drawView.startNew();
                    dialog.dismiss();
                }
            });
            newDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            newDialog.show();
        }


        else if(view.getId()==R.id.save_btn){
            //save drawing
            AlertDialog.Builder saveDialog = new AlertDialog.Builder(this);
            saveDialog.setTitle("Save drawing");
            saveDialog.setMessage("Save drawing to device Gallery?");
            saveDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    //save drawing
                    drawView.setDrawingCacheEnabled(true);
                    //attempt to save
                    String imgSaved = MediaStore.Images.Media.insertImage(
                            getContentResolver(), drawView.getDrawingCache(),
                            UUID.randomUUID().toString()+".png", "drawing");
                    //feedback
                    if(imgSaved!=null){
                        Toast savedToast = Toast.makeText(getApplicationContext(), 
                                "Drawing saved to Gallery!", Toast.LENGTH_SHORT);
                        savedToast.show();
                    }
                    else{
                        Toast unsavedToast = Toast.makeText(getApplicationContext(), 
                                "Oops! Image could not be saved.", Toast.LENGTH_SHORT);
                        unsavedToast.show();
                    }
                    drawView.destroyDrawingCache();
                }
            });
            saveDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            saveDialog.show();
        }










        else if(view.getId()==R.id.GalleryButton){
            //new button
            AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
            newDialog.setTitle("New drawing");
            newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
            newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    Intent choosePictureIntent = new Intent(
                            Intent.ACTION_PICK,
                            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                    startActivityForResult(choosePictureIntent, 101);


                }

            });
            newDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            newDialog.show();
        }


    }
















    public void  setDrawingThemefrmGallery()
    {

        Intent pickPhoto = new Intent(
                Intent.ACTION_PICK,
                android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(pickPhoto, GALLERY_INTENT_CALLED);

    }

    public static Bitmap drawableToBitmap (Drawable drawable) {
        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable)drawable).getBitmap();
        }

        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap); 
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);

        return bitmap;
    }



    protected void onActivityResult(int requestCode, int resultCode,
            Intent returnedIntent) {
        drawView.drawImage(drawableToBitmap(image));
        super.onActivityResult(requestCode, resultCode, returnedIntent);
    if (requestCode ==  GALLERY_INTENT_CALLED) {
        if (resultCode == RESULT_OK) {
            try {
                Uri selectedImage = returnedIntent.getData();
                InputStream inputStream = getContentResolver().openInputStream(selectedImage);
                image = Drawable.createFromStream(inputStream, selectedImage.toString());
            } catch (FileNotFoundException e) {}
        }
    }
}













}

My DrawingView Class ---

package com.example.drawingfun;

import java.io.File;

import android.view.View;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore;
import android.util.AttributeSet;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.CornerPathEffect;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Shader;
import android.view.MotionEvent;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.TypedValue;



public class DrawingView extends View {

    //drawing path
    private Path drawPath;
    //drawing and canvas paint
    private Paint drawPaint, canvasPaint;
    //initial color
    private int paintColor = 0xFF660000;
    //canvas
    private Canvas drawCanvas;
    //canvas bitmap
    private Bitmap canvasBitmap;
    private float brushSize, lastBrushSize;
    private boolean erase=false;



    public DrawingView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setupDrawing();
        // TODO Auto-generated constructor stub
    }

    private void setupDrawing() {
        // TODO Auto-generated method stub



        brushSize = getResources().getInteger(R.integer.medium_size);
        lastBrushSize = brushSize;



        drawPath = new Path();
        drawPaint = new Paint();
        drawPaint.setColor(paintColor);

        drawPaint.setAntiAlias(true);
        drawPaint.setStrokeWidth(brushSize);
        drawPaint.setStyle(Paint.Style.FILL_AND_STROKE);
        drawPaint.setStrokeJoin(Paint.Join.ROUND);
        drawPaint.setStrokeCap(Paint.Cap.ROUND);


        canvasPaint = new Paint(Paint.DITHER_FLAG);




    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        //view given size
        super.onSizeChanged(w, h, oldw, oldh);
        canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        drawCanvas = new Canvas(canvasBitmap);
        }

    @Override
    protected void onDraw(Canvas canvas) {
    //draw view
        canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
        canvas.drawPath(drawPath, drawPaint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
    //detect user touch
        float touchX = event.getX();
        float touchY = event.getY();
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            drawPath.moveTo(touchX, touchY);
            break;
        case MotionEvent.ACTION_MOVE:
            drawPath.lineTo(touchX, touchY);
            break;
        case MotionEvent.ACTION_UP:
            drawPath.lineTo(touchX, touchY);
            drawCanvas.drawPath(drawPath, drawPaint);
            drawPath.reset();
            break;
        default:
            return false;
        }
        invalidate();
        return true;
    }

    public void setColor(String newColor){
        //set color
        invalidate();
        if(newColor.startsWith("#")){
            paintColor = Color.parseColor(newColor);
            drawPaint.setColor(paintColor);
            drawPaint.setShader(null);
        }
        else{
            //pattern
            int patternID = getResources().getIdentifier(
                    newColor, "drawable", "com.example.drawingfun");
            //decode 
            Bitmap patternBMP = BitmapFactory.decodeResource(getResources(), patternID);
            //create shader
            BitmapShader patternBMPshader = new BitmapShader(patternBMP, 
                    Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);  
            //color and shader
            drawPaint.setColor(0xFFFFFFFF);
            drawPaint.setShader(patternBMPshader);
        }
        }

    public void setBrushSize(float newSize){
        //update size
        float pixelAmount = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
                newSize, getResources().getDisplayMetrics());
            brushSize=pixelAmount;
            drawPaint.setStrokeWidth(brushSize);
        }

    public void setLastBrushSize(float lastSize){
        lastBrushSize=lastSize;
    }
    public float getLastBrushSize(){
        return lastBrushSize;
    }


    public void setErase(boolean isErase){
        //set erase true or false
        erase=isErase;

        if(erase) 
        {


            paintColor = Color.parseColor("WHITE");
            drawPaint.setColor(paintColor);
            //drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
            drawPaint.setShader(null);





        }

        else 


            drawPaint.setXfermode(null);

        }

    public void startNew(){
        drawCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
        invalidate();
    }





    public void drawImage(Bitmap image) {
        drawCanvas.drawBitmap(image, 0, 0, canvasPaint);
        invalidate();
    }















    }
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1 answer

, Canvas.

, , .

:

public class DrawView extends View{

    private Paint bufferPaint;
    private Bitmap buffer;
    private Canvas board;
    private Path currPath;

    public DrawView(Context context) {
        super(context);
        bufferPaint = new Paint(Paint.DITHER_FLAG);
    }

    public void init() {
        buffer = Bitmap.createBitmap(getWidth(), getHeight(),
                Bitmap.Config.ARGB_8888);
        board = new Canvas(buffer);
        invalidate();
    }

    public void drawBitmap(Bitmap bitmap) {
        board.drawBitmap(bitmap, 0, 0, bufferPaint)
    }

    @Override
    public void onDraw(Canvas canvas) {
        if (buffer != null) {
            canvas.drawBitmap(buffer, 0, 0, bufferPaint);
        }
    }
}

drawBitmap . canvas (board) .

int GALLERY_INTENT_CALLED = 3; // has to be a unique request code
Drawable image;

,

Intent pickPhoto = new Intent(
                Intent.ACTION_PICK,
                android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(pickPhoto, GALLERY_INTENT_CALLED);

onActivityResult,

protected void onActivityResult(int requestCode, int resultCode,
            Intent returnedIntent) {
        super.onActivityResult(requestCode, resultCode, returnedIntent);
    if (requestCode ==  CAMERA_INTENT_CALLED) {
        if (resultCode == RESULT_OK) {
            try {
                Uri selectedImage = returnedIntent.getData()
                InputStream inputStream = getContentResolver().openInputStream(selectedImage);
                image = Drawable.createFromStream(inputStream, selectedImage.toString());
            } catch (FileNotFoundException e) {}
        }
    }
}

DrawingView

public void drawImage(Bitmap image) {
    drawCanvas.drawBitmap(image, 0, 0, canvasPaint);
    invalidate();
}

, :

public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

, Mainactivity

drawView.drawImage(drawableToBitmap(image))
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