Android-based tablet and graffiti Functions

Android-based tablet and graffiti Functions

The following code is used to simulate an Android tablet and graffiti:

Write_pad.xml

 

 
  
<Framelayout android: id = "@ + id/tablet_view" android: layout_height = "300dp" android: layout_width = "fill_parent"> </framelayout>
  
   
   
   
  
 

 

This is the main layout file of the tablet, and the hand-written part is a FrameLayout. The buttons "OK", "clear", and "cancel" are provided to save and erase the signature.

 

The main code logic is as follows:

MainActivity. java

Package com. jackie. handwriting; import java. io. byteArrayOutputStream; import java. io. file; import java. io. fileOutputStream; import java. io. IOException; import android. app. activity; import android. graphics. bitmap; import android. OS. bundle; import android. OS. environment; import android. view. view; import android. view. view. onClickListener; import android. widget. imageView; import android. widget. textView; public clas S MainActivity extends Activity {private ImageView mIVSign; private TextView mTVSign; private Bitmap mSignBitmap;/** Called when the activity is first created. * // @ Overridepublic void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); mIVSign = (ImageView) findViewById (R. id. iv_sign); mTVSign = (TextView) findViewById (R. id. TV _sign); mTVSign. set OnClickListener (new OnClickListener () {@ Overridepublic void onClick (View view) {WritePadDialog mWritePadDialog = new WritePadDialog (MainActivity. this, new WriteDialogListener () {@ Overridepublic void onPaintDone (Object object) {mSignBitmap = (Bitmap) object; createSignFile (); mIVSign. setImageBitmap (mSignBitmap); mTVSign. setVisibility (View. GONE) ;}}); mWritePadDialog. show () ;}}) ;}// create the private void crea signature file. TeSignFile () {ByteArrayOutputStream baos = null; FileOutputStream fos = null; String path = null; File file = null; try {path = Environment. getExternalStorageDirectory () + File. separator + System. currentTimeMillis () + ". jpg "; file = new File (path); fos = new FileOutputStream (file); baos = new ByteArrayOutputStream (); // if it is set to Bitmap. compress (CompressFormat. JPEG, 100, fos) the image background is black mSignBitmap. co Mpress (Bitmap. CompressFormat. PNG, 100, baos); byte [] B = baos. toByteArray (); if (B! = Null) {fos. write (B) ;}} catch (IOException e) {e. printStackTrace () ;}finally {try {if (fos! = Null) {fos. close ();} if (baos! = Null) {baos. close () ;}} catch (IOException e) {e. printStackTrace ();}}}}

 

PaintView. java

Package com. jackie. handwriting; import android. content. context; import android. graphics. bitmap; import android. graphics. bitmap. config; import android. graphics. canvas; import android. graphics. color; import android. graphics. matrix; import android. graphics. paint; import android. graphics. path; import android. graphics. porterDuff; import android. view. motionEvent; import android. view. view; public class PaintView exte Nds View {private Paint mPaint; private Path mPath; private Bitmap mBitmap; private Canvas mCanvas; private int screenWidth, screenHeight; private float currentX, currentY; public PaintView (Context context, int screenWidth, int screenHeight) {super (context); this. screenWidth = screenWidth; this. screenHeight = screenHeight; init ();} private void init () {mPaint = new Paint (); mPaint. setAntiAlias (true); // remove the Sawtooth MPaint. setStrokeWidth (5); mPaint. setStyle (Paint. style. STROKE); mPaint. setColor (Color. BLACK); mPath = new Path (); mBitmap = Bitmap. createBitmap (screenWidth, screenHeight, Config. ARGB_8888); mCanvas = new Canvas (mBitmap); // mCanvas. drawColor (Color. WHITE) ;}@ Overrideprotected void onDraw (Canvas canvas) {canvas. drawBitmap (mBitmap, 0, 0, null); canvas. drawPath (mPath, mPaint);} @ Overridepublic boolean onTouchEve Nt (MotionEvent event) {float x = event. getX (); float y = event. getY (); switch (event. getAction () {case MotionEvent. ACTION_DOWN: currentX = x; currentY = y; mPath. moveTo (currentX, currentY); break; case MotionEvent. ACTION_MOVE: currentX = x; currentY = y; mPath. quadTo (currentX, currentY, x, y); // draw line break; case MotionEvent. ACTION_UP: mCanvas. drawPath (mPath, mPaint); break;} invalidate (); return true;} public Bitm Ap getPaintBitmap () {return resizeImage (mBitmap, 320,480);} public Path getPath () {return mPath;} // scale public static Bitmap resizeImage (Bitmap bitmap, int width, int height) {int originWidth = bitmap. getWidth (); int originHeight = bitmap. getHeight (); float scaleWidth = (float) width)/originWidth; float scaleHeight = (float) height)/originHeight; Matrix matrix = new Matrix (); matrix. postScale (scale Width, scaleHeight); Bitmap resizedBitmap = Bitmap. createBitmap (bitmap, 0, 0, originWidth, originHeight, matrix, true); return resizedBitmap;} // clear the canvas public void clear () {if (mCanvas! = Null) {mPath. reset (); mCanvas. drawColor (Color. TRANSPARENT, PorterDuff. Mode. CLEAR); invalidate ();}}}

 

WritePadDialog. java

 

Package com. jackie. handwriting; import android. app. dialog; import android. content. context; import android. OS. bundle; import android. util. displayMetrics; import android. view. view; import android. view. window; import android. widget. button; import android. widget. frameLayout; import android. widget. toast; public class WritePadDialog extends Dialog {private Context mContext; private PaintView mPaintView; private FrameLayout comment; private Button mBtnOK, mBtnClear, mBtnCancel; public WritePadDialog (Context context Context, writeDialogListener writeDialogListener) {super (context); this. mContext = context; this. mWriteDialogListener = writeDialogListener;} @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); requestWindowFeature (Window. FEATURE_NO_TITLE); // setContentView (R. layout. write_pad); mFrameLayout = (FrameLayout) findViewById (R. id. tablet_view); // obtain the screen size DisplayMetrics mDisplayMetrics = new DisplayMetrics (); getWindow (). getWindowManager (). getdefadisplay display (). getMetrics (mDisplayMetrics); int screenWidth = mDisplayMetrics. widthPixels; int screenHeight = mDisplayMetrics. heightPixels; mPaintView = new PaintView (mContext, screenWidth, screenHeight); mFrameLayout. addView (mPaintView); mPaintView. requestFocus (); mBtnOK = (Button) findViewById (R. id. write_pad_ OK); mBtnOK. setOnClickListener (new View. onClickListener () {@ Overridepublic void onClick (View v) {if (mPaintView. getPath (). isEmpty () {Toast. makeText (mContext, "please write down your name", Toast. LENGTH_SHORT ). show (); return;} mWriteDialogListener. onPaintDone (mPaintView. getPaintBitmap (); dismiss () ;}}); mBtnClear = (Button) findViewById (R. id. write_pad_clear); mBtnClear. setOnClickListener (new View. onClickListener () {@ Overridepublic void onClick (View v) {mPaintView. clear () ;}}); mBtnCancel = (Button) findViewById (R. id. write_pad_cancel); mBtnCancel. setOnClickListener (new View. onClickListener () {@ Overridepublic void onClick (View v) {cancel ();}});}}

 

WriteDilogListener. java

 

Package com. jackie. handwriting;/*** dialog box * @ author chengcj1 ***/public interface WriteDialogListener {public void onPaintDone (Object object Object );}

 

The effect is as follows: