Java tutorial
/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.apis.graphics; import org.apache.commons.io.output.ByteArrayOutputStream; import org.liberty.android.fantastischmemo.R; import android.content.Context; import android.content.SharedPreferences; import android.content.SharedPreferences.Editor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.BlurMaskFilter; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.EmbossMaskFilter; import android.graphics.MaskFilter; import android.graphics.Paint; import android.graphics.Path; import android.graphics.PorterDuff; import android.graphics.PorterDuffXfermode; import android.os.Bundle; import android.preference.PreferenceManager; import android.util.Base64; import android.view.Display; import android.view.Menu; import android.view.MenuItem; import android.view.MotionEvent; import android.view.View; public class FingerPaint extends GraphicsActivity implements ColorPickerDialog.OnColorChangedListener { private MyView myView; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bitmap loadedBitmap = loadBitmap(); myView = new MyView(this, loadedBitmap); setContentView(myView); mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setDither(true); mPaint.setColor(0xFFFF0000); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeJoin(Paint.Join.ROUND); mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeWidth(12); mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f); mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL); setTitle(R.string.paint_text); } @Override public void onDestroy() { saveBitmap(myView.getBitmap()); super.onDestroy(); } private Paint mPaint; private MaskFilter mEmboss; private MaskFilter mBlur; public void colorChanged(int color) { mPaint.setColor(color); } public class MyView extends View { @SuppressWarnings("unused") private static final float MINP = 0.25f; @SuppressWarnings("unused") private static final float MAXP = 0.75f; private Bitmap mBitmap; private Canvas mCanvas; private Path mPath; private Paint mBitmapPaint; public MyView(Context c, Bitmap bitmap) { super(c); mBitmap = bitmap; mCanvas = new Canvas(mBitmap); mPath = 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); } @Override protected void onDraw(Canvas canvas) { canvas.drawColor(0x6FAAAAAA); canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint); canvas.drawPath(mPath, mPaint); } private float mX, mY; private static final float TOUCH_TOLERANCE = 4; private void touch_start(float x, float y) { mPath.reset(); mPath.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) { mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2); mX = x; mY = y; } } private void touch_up() { mPath.lineTo(mX, mY); // commit the path to our offscreen mCanvas.drawPath(mPath, mPaint); // kill this so we don't double draw mPath.reset(); } @Override public boolean onTouchEvent(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; } public Bitmap getBitmap() { return mBitmap; } } private static final int COLOR_MENU_ID = Menu.FIRST; private static final int EMBOSS_MENU_ID = Menu.FIRST + 1; private static final int BLUR_MENU_ID = Menu.FIRST + 2; private static final int ERASE_MENU_ID = Menu.FIRST + 3; private static final int SRCATOP_MENU_ID = Menu.FIRST + 4; private static final int ERASE_ALL_ID = Menu.FIRST + 5; @Override public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); menu.add(0, ERASE_ALL_ID, 0, "Erase all").setShortcut('3', 'a'); menu.add(0, COLOR_MENU_ID, 0, "Color").setShortcut('3', 'c'); menu.add(0, EMBOSS_MENU_ID, 0, "Emboss").setShortcut('4', 's'); menu.add(0, BLUR_MENU_ID, 0, "Blur").setShortcut('5', 'z'); menu.add(0, ERASE_MENU_ID, 0, "Erase").setShortcut('5', 'z'); menu.add(0, SRCATOP_MENU_ID, 0, "SrcATop").setShortcut('5', 'z'); /**** Is this the mechanism to extend with filter effects? Intent intent = new Intent(null, getIntent().getData()); intent.addCategory(Intent.CATEGORY_ALTERNATIVE); menu.addIntentOptions( Menu.ALTERNATIVE, 0, new ComponentName(this, NotesList.class), null, intent, 0, null); *****/ return true; } @Override public boolean onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { mPaint.setXfermode(null); mPaint.setAlpha(0xFF); switch (item.getItemId()) { case ERASE_ALL_ID: myView.getBitmap().eraseColor(Color.TRANSPARENT); myView.invalidate(); return true; case COLOR_MENU_ID: new ColorPickerDialog(this, this, mPaint.getColor()).show(); return true; case EMBOSS_MENU_ID: if (mPaint.getMaskFilter() != mEmboss) { mPaint.setMaskFilter(mEmboss); } else { mPaint.setMaskFilter(null); } return true; case BLUR_MENU_ID: if (mPaint.getMaskFilter() != mBlur) { mPaint.setMaskFilter(mBlur); } else { mPaint.setMaskFilter(null); } return true; case ERASE_MENU_ID: mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR)); return true; case SRCATOP_MENU_ID: mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_ATOP)); mPaint.setAlpha(0x80); return true; } return super.onOptionsItemSelected(item); } private Bitmap loadBitmap() { SharedPreferences shre = PreferenceManager.getDefaultSharedPreferences(this); String previouslyEncodedImage = shre.getString("paint_image_data", ""); if (!previouslyEncodedImage.equalsIgnoreCase("")) { byte[] b = Base64.decode(previouslyEncodedImage, Base64.DEFAULT); Bitmap bitmap = BitmapFactory.decodeByteArray(b, 0, b.length); Bitmap mutableBitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true); return mutableBitmap; } Display display = getWindowManager().getDefaultDisplay(); @SuppressWarnings("deprecation") int width = display.getWidth(); @SuppressWarnings("deprecation") int height = display.getHeight(); Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); return bitmap; } private void saveBitmap(Bitmap bitmap) { ByteArrayOutputStream baos = new ByteArrayOutputStream(); bitmap.compress(Bitmap.CompressFormat.PNG, 0, baos); byte[] b = baos.toByteArray(); String encodedImage = Base64.encodeToString(b, Base64.DEFAULT); SharedPreferences shre = PreferenceManager.getDefaultSharedPreferences(this); Editor edit = shre.edit(); edit.putString("paint_image_data", encodedImage); edit.commit(); } }