Develop Reference

Load a Image from SDCard to DrawingView

I'm a newbie for android development. I need some help with loading image from SDCard to a drawingView. What I'm trying to achieve here is after loading the image i want to modify the image and save.
So my primary task is to load the image to DrawingView.
Appreciate your help on this.
Thank you.

please use something like this ..this worked for me
YourDrawingView jpgView = (YourDrawingView)findViewById(R.id.imageView);
Bitmap bitmap = BitmapFactory.decodeFile("/sdcard/sample-1.jpg");
jpgView.setImageBitmap(bitmap);
setContentView(R.layout.main);
and here is my DrawingView
public class DrawingView extends ImageView {
private boolean erase = false;
//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;
public DrawingView(Context context, AttributeSet attrs) {
super(context, attrs);
setUpDrawing();
}
public DrawingView(Context context) {
super(context);
}
private void setUpDrawing() {
drawPath = new Path();
drawPaint = new Paint();
drawPaint.setColor(paintColor);
drawPaint.setAntiAlias(true);
drawPaint.setStrokeWidth(20);
drawPaint.setStyle(Paint.Style.STROKE);
drawPaint.setStrokeJoin(Paint.Join.ROUND);
drawPaint.setStrokeCap(Paint.Cap.ROUND);
canvasPaint = new Paint(Paint.DITHER_FLAG);
brushSize = getResources().getInteger(R.integer.medium_size);
lastBrushSize = brushSize;
drawPaint.setStrokeWidth(brushSize);
}
public void setErase(boolean isErase) {
//set erase true or false
erase = isErase;
if (erase) drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
else drawPaint.setXfermode(null);
}
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;
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
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) {
super.onDraw(canvas);
canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
canvas.drawPath(drawPath, drawPaint);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
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:
drawCanvas.drawPath(drawPath, drawPaint);
drawPath.reset();
break;
default:
break;
}
invalidate();
return true;
}
public void setColor(String color) {
invalidate();
paintColor = Color.parseColor(color);
drawPaint.setColor(paintColor);
}
public void startNew() {
drawCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
invalidate();
}
}

Not sure what is DrawingView, or do you mean ImageView?
File imageFile = new File("/sdcard/my_photo_1.jpg");
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
imageView.setImageBitmap(bitmap);

You can use canvas to draw image, Below is code :
public class Keypaint extends View {
Paint p;
Bitmap bitmap = null;
public Keypaint(Context context) {
super(context);
File imageFile = new File("/sdcard/my_photo_1.jpg");
bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
p=new Paint();
p.setColor(Color.RED);
canvas.drawBitmap(bitmap, 0, 0, p);
}
}

Emboss bitmap on touch in android

I am developing color splash app. in which i use finger paint.
Now i want to emboss bitmap on touch event. i have one demo here in which when i apply emboss then it draw emboss path with red color but i want to emboss behind bitmap on touch.
private Path mPath;
private MaskFilter mEmboss;
public void init(){
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(color.RED);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(20);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f);
}
// on click event
switch (item.getItemId()) {
case EMBOSS_MENU_ID:
mPaint.setMaskFilter(mEmboss);
}
// View Class method
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(mPath, mPaint);
canvas.drawPath(circlePath, circlePaint);
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
float x = ev.getX();
float y = ev.getY();
invalidate();
return true;
}

I eventually find the solution:
Use BitmapShader with same bitmap
private Path mPath;
private MaskFilter mEmboss;
public void init(){
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(color.RED);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(20);
BitmapShader fillBMPshader = new BitmapShader(bm_original, Shader.TileMode.MIRROR, Shader.TileMode.CLAMP);
mPaint.setShader(fillBMPshader);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f);
}
// onclick event
switch (item.getItemId()) {
case EMBOSS_MENU_ID:
mPaint.setMaskFilter(mEmboss);
}
// View Class method
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(mPath, mPaint);
canvas.drawPath(circlePath, circlePaint);
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
float x = ev.getX();
float y = ev.getY();
invalidate();
return true;
}

How to Draw line with different color and size?

When i choose initially red and draw a line, and then later select blue and draw a line , now the older line is also getting changed to blue instead of red, However i want the red to remain as red, and blue as such can any one help?
I also tried to get this solution online bt not solve my problem.so please help me.
DrawingView.java
public class DrawingView extends View {
Paint mPaint;
Path mpath;
Canvas mCanvas;
Bitmap myBitmap;
//initial color
private int paintColor = 0xFF660000;
private ArrayList<PathWithPaint> _graphics1 = new ArrayList<PathWithPaint>();
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
// private Map<Path,Float> stoWid = new HashMap<Path,Float>();
private Map<Path, Integer> colorsMap = new HashMap<Path, Integer>();
public DrawingView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
Drawingsetup();
}
private void Drawingsetup() {
// TODO Auto-generated method stub
mPaint = new Paint();
mpath = new Path();
mCanvas = new Canvas();
mPaint.setDither(true);
mPaint.setColor(0xFFFFFFFF);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.BEVEL);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
// TODO Auto-generated method stub
super.onSizeChanged(w, h, oldw, oldh);
myBitmap = Bitmap.createBitmap(820, 480, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(myBitmap);
mCanvas.drawBitmap(myBitmap, 20, 20, mPaint);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
//return super.onTouchEvent(event);
PathWithPaint pp = new PathWithPaint();
//mCanvas.drawPath(path, mPaint);
if (event.getAction() == MotionEvent.ACTION_DOWN) {
undonePaths.clear();
mpath.moveTo(event.getX(), event.getY());
mpath.lineTo(event.getX(), event.getY());
} else if (event.getAction() == MotionEvent.ACTION_MOVE) {
mpath.lineTo(event.getX(), event.getY());
pp.setPath(mpath);
pp.setmPaint(mPaint);
_graphics1.add(pp);
} else if (event.getAction()==MotionEvent.ACTION_UP) {
mpath.lineTo(event.getX(), event.getY());
// commit the path to our offscreen
mCanvas.drawPath(mpath, mPaint);
// kill this so we don't double draw
paths.add(mpath);
mpath = new Path();
colorsMap.put(mpath,paintColor); // store the color of mPath
}
invalidate();
return true;
}
#Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
//canvas.drawBitmap(myBitmap, 0, 0, mPaint);
for(Path p: paths){
canvas.drawPath(p, mPaint);
mPaint.setColor(colorsMap.get(p));
}
canvas.drawPath(mpath, mPaint);
canvas.setColor(paintColor);
}
public void CurrentDraw(){
}
public void StartNew(){
//colorsMap.clear();
undonePaths.clear();
paths.clear();
myBitmap.eraseColor(Color.TRANSPARENT);
mpath.reset();
invalidate();
_graphics1.clear();
}
public void ColorChanged(String newColor){
//set color
// start by invalidating the View
//parse and set the color for drawing
paintColor = Color.parseColor(newColor);
mPaint.setColor(paintColor);
invalidate();
}
public void onClickUndo()
{
if (paths.size()>0) {
undonePaths.add(paths.remove(paths.size()-1));
invalidate();
}
else
{
}
}
public void onClickRedo (){
if (undonePaths.size()>0) {
paths.add(undonePaths.remove(undonePaths.size()-1));
invalidate();
}
else
{
}
}
}
DrawingActivity.java
public class DrwaingActivity extends Activity {
DrawingView drawView;
Bitmap myBitmap;
private ImageButton currentpaint ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.draw_image);
//get drawing view
drawView = (DrawingView)findViewById(R.id.drawing);
// drawView.setOnClickListener(this);
//get the palette and first color button
LinearLayout paintLayout = (LinearLayout)findViewById(R.id.paint_colors);
currentpaint = (ImageButton)paintLayout.getChildAt(0);
currentpaint.setImageDrawable(getResources().getDrawable(R.drawable.paint));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_item, menu);
return true;
}
public void paintClicked(View view){
if(view!=currentpaint)
{
//update color
// retrieve the tag we set for each button in the layout, representing the chosen color
ImageButton imgView = (ImageButton)view;
String color = view.getTag().toString();
// call the new method on the custom drawing View object
drawView.ColorChanged(color);
// update the UI to reflect the new chosen paint and set the previous one back to normal
imgView.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));
currentpaint.setImageDrawable(getResources().getDrawable(R.drawable.paint));
currentpaint=(ImageButton)view;
}
}

Clear canvas in button click

I used following code to draw. I want to clear the previously drawn lines if the clear button is clicked.
public class MainActivity extends Activity {
private ArrayList<Path> _graphics = new ArrayList<Path>();
private Paint mPaint;
Activity activity;
View mView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
activity = this;
mView = new DrawingView(this);
activity.addContentView(mView, new LayoutParams(500,
LinearLayout.LayoutParams.WRAP_CONTENT));
init();
}
public void clear(View v) {
new DrawingView(activity).clearView();
}
private void init() {
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(0xFFFFFF00);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
}
class DrawingView extends View {
private Path path;
public DrawingView(Context context) {
super(context);
path = new Path();
this.setBackgroundColor(Color.BLACK);
}
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
path.moveTo(event.getX(), event.getY());
path.lineTo(event.getX(), event.getY());
} else if (event.getAction() == MotionEvent.ACTION_MOVE) {
path.lineTo(event.getX(), event.getY());
} else if (event.getAction() == MotionEvent.ACTION_UP) {
path.lineTo(event.getX(), event.getY());
_graphics.add(path);
}
invalidate();
return true;
}
#Override
public void onDraw(Canvas canvas) {
for (Path path : _graphics) {
canvas.drawPath(path, mPaint);
}
}
public void clearView() {
path = new Path();
invalidate();
}
}
}
Thank you.

import android.graphics.Color;
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.TRANSPARENT);
for (Path path : _graphics) {
canvas.drawPath(path, mPaint);
}
}
or
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
mPaint.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
canvas.drawPaint(mPaint);
mPaint.setXfermode(new PorterDuffXfermode(Mode.SRC));
for (Path path : _graphics) {
canvas.drawPath(path, mPaint);
}
}
See this Doc for more info.
Your clear method is wrong.
public void clear(View v) {
((DrawingView)mView).clearView();
}

Add the below in your Drawing view
Bitmap mBitmap;
Paint mPaint;
Canvas mCanvas;
int width,height;
public void clear()
{
_graphics.removeAll(_graphics);
mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
path = new Path();
invalidate();
}
Also add the below
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width = w;
height = h;
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
In your onDraw add the below
canvas.drawBitmap(mBitmap, 0, 0, null);
To clear on button click
mView.clear();

This code works for me
clearbtn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mBitmap.eraseColor(Color.TRANSPARENT);
mPath.reset();
mView.invalidate();
}
});

this method work for me,
public void Clear()
{
mBitmap.eraseColor(Color.TRANSPARENT);
mPath.reset();
invalidate();
}

How to erase line drawn on a canvas?

I am using a Canvas class to draw lines on the canvas. Now I want to erase line drawn in the canvas in a similar way as we do in our notebook using an eraser. I go through several examples but nothing works for me.
If anyone knows a solution to this problem, please could you help me to solve this?
Java Code:
public class DrawView extends View implements OnTouchListener
{
private Canvas m_Canvas;
private Path m_Path;
private Paint m_Paint;
ArrayList<Pair<Path, Paint>> paths = new ArrayList<Pair<Path, Paint>>();
ArrayList<Pair<Path, Paint>> undonePaths = new ArrayList<Pair<Path, Paint>>();
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private Bitmap bitmapToCanvas;
private CanvasManager m_CanvasManagerObject;
private Paint mBitmapPaint;
public DrawView(Context context)
{
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
this.setOnTouchListener(this);
onCanvasInitialization();
}
public void onCanvasInitialization()
{
m_Paint = new Paint(Paint.DITHER_FLAG);
m_Paint.setAntiAlias(true);
m_Paint.setDither(true);
m_Paint.setColor(Color.parseColor("#37A1D1"));
m_Paint.setStyle(Paint.Style.STROKE);
m_Paint.setStrokeJoin(Paint.Join.ROUND);
m_Paint.setStrokeCap(Paint.Cap.ROUND);
m_Paint.setStrokeWidth(2);
m_Path = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh)
{
super.onSizeChanged(w, h, oldw, oldh);
bitmapToCanvas = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
m_Canvas = new Canvas(bitmapToCanvas);
}
#Override
protected void onDraw(Canvas canvas)
{
canvas.drawBitmap(bitmapToCanvas, 0f, 0f, mBitmapPaint);
canvas.drawPath(m_Path, m_Paint);
}
public boolean onTouch(View arg0, MotionEvent event)
{
float x = event.getX();
float y = event.getY();
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
private void touch_start(float x, float y)
{
m_Path.reset();
m_Path.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y)
{
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE)
{
m_Path.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up()
{
m_Path.lineTo(mX, mY);
// commit the path to our offscreen
m_Canvas.drawPath(m_Path, m_Paint);
// kill this so we don't double draw
Paint newPaint = new Paint(m_Paint); // Clones the mPaint object
paths.add(new Pair<Path, Paint>(m_Path, newPaint));
m_Path = new Path();
}
public void onClickEraser()
{
}
}

If you have solid color background all you need to do is set Paint color to your background color. For example, if you have a white background you can do:
paint.setColor(Color.White);
However, if you need to erase a line with a transparent background you try this:
In order to draw with a transparent color you must use Paint setXfermode which will only work if you set a bitmap to your canvas. If you follow the steps below you should get the desired result.
Create a canvas and set its bitmap.
mCanvas = new Canvas();
mBitmap= Bitmap.createBitmap(scrw, scrh, Config.ARGB_8888);
mCanvas.setBitmap(mBitmap);
When you want to erase something you just need to use setXfermode.
public void onClickEraser()
{
if (isEraserOn)
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
else
mPaint.setXfermode(null);
}
Now you should be able draw with a transparent color using:
mCanvas.drawPath(path, mPaint);

on par with the answer of Daniel Albert,
after using:
public void onClickEraser()
{
if (isEraserOn)
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
else
mPaint.setXfermode(null);
}
…you should commit every paint on your touch_move method to avoid solid path . and disable also drawpath if isErase = true

in order to erase, besides the brush color, you need to set the background color too.
please imagine that you are using a mspaint, the eraser itself is "painting" the background color on the canva.
if your background is 000
then the delbrush could be like
delPaint = new Paint();
delPaint.setColor(0x00000000);
delPaint.setXfermode(clear);
delPaint.setAlpha(0x00);
delPaint.setAntiAlias(true);
delPaint.setDither(true);
delPaint.setStyle(Paint.Style.STROKE);
delPaint.setStrokeJoin(Paint.Join.ROUND);
delPaint.setStrokeCap(Paint.Cap.ROUND);

relativeLayout = (RelativeLayout) findViewById(R.id.relativelayout1);
button = (Button)findViewById(R.id.button);
view = new SketchSheetView(slate.this);
paint = new Paint();
path2 = new Path();
relativeLayout.addView(view, new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT));
paint.setDither(true);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(5);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
path2.reset();
relativeLayout.removeAllViewsInLayout();
view = new SketchSheetView(slate.this);
relativeLayout.addView(view, new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT));
}
});
}
private class SketchSheetView extends View {
public SketchSheetView(slate slate) {
super(slate);
bitmap = Bitmap.createBitmap(820, 480, Bitmap.Config.ARGB_4444);
canvas = new Canvas(bitmap);
this.setBackgroundColor(Color.WHITE);
}
ArrayList<DrawingClass> DrawingClassArrayList= new ArrayList<DrawingClass>();
#Override
public boolean onTouchEvent(MotionEvent event) {
DrawingClass pathWithPaint = new DrawingClass();
canvas.drawPath(path2, paint);
if (event.getAction() == MotionEvent.ACTION_DOWN) {
path2.moveTo(event.getX(), event.getY());
path2.lineTo(event.getX(), event.getY());
}
else if (event.getAction() == MotionEvent.ACTION_MOVE) {
path2.lineTo(event.getX(), event.getY());
pathWithPaint.setPath(path2);
pathWithPaint.setPaint(paint);
DrawingClassArrayList.add(pathWithPaint);
}
invalidate();
return true;
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (DrawingClassArrayList.size() > 0) {
canvas.drawPath(
DrawingClassArrayList.get(DrawingClassArrayList.size() - 1).getPath(),
DrawingClassArrayList.get(DrawingClassArrayList.size() - 1).getPaint());
}
}
}
public class DrawingClass {
Path DrawingClassPath;
Paint DrawingClassPaint;
public Path getPath() {
return DrawingClassPath;
}
public void setPath(Path path) {
this.DrawingClassPath = path;
}
public Paint getPaint() {
return DrawingClassPaint;
}
public void setPaint(Paint paint) {
this.DrawingClassPaint = paint;
}
}