Android draw step 6: Draw touch tracks and save images

Because many of the Code has been designed for the first five advanced steps, we will not repeat them here. List the core code.
Part 1: xml file
Select an image with one button and save the image with one button
The Code is as follows:
1. <? Xml version = "1.0" encoding = "UTF-8"?>
2. <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
3. android: layout_width = "fill_parent"
4. android: layout_height = "fill_parent"
5. android: orientation = "vertical">
6.
7. <Button
8. android: id = "@ + id/pickImageBtn"
9. android: layout_width = "wrap_content"
10. android: layout_height = "wrap_content"
11. android: text = "pickImage"/>
12.
13. <ImageView
14. android: id = "@ + id/pickedImage"
15. android: layout_width = "wrap_content"
16. android: layout_height = "wrap_content"
17. android: src = "@ drawable/ic_launcher"/>
18.
19. <Button
20. android: id = "@ + id/saveBtn"
21. android: layout_width = "wrap_content"
22. android: layout_height = "wrap_content"
23. android: text = "Save"/>
24.
25. </LinearLayout>
Part 2: initialization
The Code is as follows:
1. public void onCreate (Bundle savedInstanceState ){
2. super. onCreate (savedInstanceState );
3. setContentView (R. layout. main );
4.
5. Button pickImageBtn = (Button) findViewById (R. id. pickImageBtn );
6. Button saveBtn = (Button) findViewById (R. id. saveBtn );
7. mImageView = (ImageView) findViewById (R. id. pickedImage );
8.
9.
10. pickImageBtn. setOnClickListener (this );
11. saveBtn. setOnClickListener (this );
12.
13.
14 .}
Part 3: Select images and listen to Touch
The Code is as follows:
 
1. public void onClick (View v ){
2. // TODO Auto-generated method stub
3. Log. d ("bitmap", "has onClick ");
4. switch (v. getId ()){
5. case R. id. pickImageBtn:
6. Intent intent = new Intent (Intent. ACTION_PICK, android. provider. MediaStore. Images. Media. EXTERNAL_CONTENT_URI );
7. startActivityForResult (intent, REQUEST_CODE );
8. break;
 
1. @ Override
2. protected void onActivityResult (int requestCode, int resultCode, Intent intent ){
3. // TODO Auto-generated method stub
4. super. onActivityResult (requestCode, resultCode, intent );
5. Log. d ("bitmap", "requestCode is:" + requestCode );
6. if (resultCode = RESULT_ OK ){
7. Log. d ("bitmap", "has result OK ");
8. Uri uri = intent. getData ();
9.
10. int dw = getWindowManager (). getdefadisplay display (). getWidth ();
11. int dh = getWindowManager (). getdefadisplay display (). getHeight ();
12.
13. try {
14. BitmapFactory. Options opts = new BitmapFactory. Options ();
15. opts. inJustDecodeBounds = true; // if it is set to true, no response is returned.
16. Bitmap chooseBitmap = BitmapFactory. decodeStream (getContentResolver (). openInputStream (uri), null, opts );
17. int bw = opts. outWidth; // at this time, the chooseBitmap value is null, but opts still obtains its config
18. int bh = opts. outHeight;
19.
20. int widthRatio = (int) Math. ceil (bw/(float) dw );
21. int heightRatio = (int) Math. ceil (bh/(float) dh );
22.
23. if (widthRatio> 1 | heightRatio> 1 ){
24. if (widthRatio> heightRatio ){
25. opts. inSampleSize = widthRatio; // set the proportion
26.} else {
27. opts. inSampleSize = heightRatio;
28 .}
29 .}
30. opts. inJustDecodeBounds = false;
31. chooseBitmap = BitmapFactory. decodeStream (getContentResolver (). openInputStream (uri), null, opts );
32. Log. d ("bitmap", "chooseBitmap is:" + chooseBitmap );
33.
34. alteredBitmap = Bitmap. createBitmap (chooseBitmap. getWidth (), chooseBitmap. getHeight (), chooseBitmap. getConfig ());
35. canvas = new Canvas (alteredBitmap); // canvas
36. paint = new Paint ();
37. paint. setColor (Color. WHITE );
38. paint. setStyle (Style. STROKE );
39. Matrix matrix = new Matrix ();
40. canvas. drawBitmap (chooseBitmap, matrix, paint );
41.
42. mImageView. setImageBitmap (alteredBitmap );
43. mImageView. setOnTouchListener (this); // set the listener
44.
45.} catch (FileNotFoundException e ){
46. // TODO Auto-generated catch block
47. e. printStackTrace ();
48 .}
49.
50.
51.
52 .}
53.
54 .}
 
Part 4: Touch and move images and draw images in real time.
The Code is as follows:
1. public boolean onTouch (View v, MotionEvent event ){
2. // TODO Auto-generated method stub
3. Log. d ("touch_draw", "ontouch ()");
4.
5. switch (event. getAction ()){
6. case MotionEvent. ACTION_UP:
7. // upX = event. getX ();
8. // upY = event. getY (); // Code related to draw a straight line. You can test it by yourself. Likewise, you can set the circle and ellipse in the relevant method.
9. // canvas. drawLine (downX, downY, upX, upY, paint );
10. // mImageView. invalidate ();
11. // break;
12. case MotionEvent. ACTION_DOWN:
13. downX = event. getX ();
14. downY = event. getY ();
15. break;
16. case MotionEvent. ACTION_MOVE:
17. upX = event. getX ();
18. upY = event. getY ();
19. canvas. drawLine (downX, downY, upX, upY, paint );
20. mImageView. invalidate ();
21. downX = upX;
22. downY = upY;
23. break;
24. case MotionEvent. ACTION_CANCEL:
25. break;
26.
27 .}
28.
29. return true;
30 .}
Part 5: save images
The Code is as follows:
 
1. public void onClick (View v ){
2. // TODO Auto-generated method stub
3. Log. d ("bitmap", "has onClick ");
4. switch (v. getId ()){
5. case R. id. pickImageBtn:
6. Intent intent = new Intent (Intent. ACTION_PICK, android. provider. MediaStore. Images. Media. EXTERNAL_CONTENT_URI );
7. startActivityForResult (intent, REQUEST_CODE );
8. break;
9. case R. id. saveBtn: // Save the graffiti Image
10.
11.
12 ./*
13. * PNG: Perfect for artistic lines and graphics: Always keep all data
14. * JPEG: Perfect for gradient full-color images, such as photos. It is a "lossy" codecs and quality can be set
15 .*/
16.
17.
18. if (null! = AlteredBitmap ){
19. Uri imageFileUri = getContentResolver (). insert (Media. EXTERNAL_CONTENT_URI, new ContentValues (); // create a new uri
20.
21. try {
22. OutputStream imageFileOS = getContentResolver (). openOutputStream (imageFileUri); // output stream
23.
24. alteredBitmap. compress (CompressFormat. JPEG, 90, imageFileOS); // generate an image
25.
26. Toast. makeText (this, "has saved", Toast. LENGTH_SHORT). show ();
27.
28.} catch (FileNotFoundException e ){
29. // TODO Auto-generated catch block
30. e. printStackTrace ();
31 .}
32 .}
33. break;
34 .}
35 .}

 
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