以下是绘图和撤消但无法加入删除的代码。
它可以是Drawing + Erasing，也可以是Drawing + Undoing，但不能有三种。
public class Drawing extends View {
private Paint mPaint, mBitmapPaint;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private int color, size, state;
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
private ArrayList<Integer> colors = new ArrayList<Integer>();
private ArrayList<Integer> sizes = new ArrayList<Integer>();
public Drawing(Context c) {
super(c);
}
public Drawing(Context c,int width, int height, int size, int color, int state) {
super(c);
mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
// mBitmapPaint = new Paint(Paint.DITHER_FLAG);
// mBitmapPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
setColor(color);
setSize(size);
setState(state);
}
@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(Color.TRANSPARENT);
// canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
//
// if (state == 0)
// mBitmap.eraseColor(Color.TRANSPARENT);
for (int i = 0; i < paths.size(); i++) {
mPaint.setColor(colors.get(i));
mPaint.setStrokeWidth(sizes.get(i));
canvas.drawPath(paths.get(i), mPaint);
}
mPaint.setColor(color);
mPaint.setStrokeWidth(size);
canvas.drawPath(mPath, mPaint);
}
public void setColor(int color) {
this.color = color;
}
public void setSize(int size) {
this.size = size;
}
public void setState(int state) {
this.state = state;
// if (state == 0)
// mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
// else
// mPaint.setXfermode(null);
}
public void onClickUndo() {
if (paths.size() > 0) {
undonePaths.add(paths.remove(paths.size() - 1));
sizes.remove(sizes.size() - 1);
colors.remove(colors.size() - 1);
invalidate();
}
}
private void touch_start(float x, float y) {
undonePaths.clear();
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);
mCanvas.drawPath(mPath, mPaint);
colors.add(color);
sizes.add(size);
paths.add(mPath);
mPath = new Path();
}
@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;
}
}
我试图将颜色变为透明，但它没有意义，因为没有更改像素但是创建了新的路径。
答案 0 :(得分：0)
以下内容可用于绘制擦除，浮雕，保存到图库，模糊。您可以使用该代码添加撤消和重做功能。以下代码工作正常。您可以在grapics文件夹中的api demos下从您adk的samples文件夹中检查FingerPaint.java。
Creating a spray effect on touch draw in android。此链接将通过喷涂点来帮助您创建喷雾效果。
public class FingerPaintActivity extends GraphicsActivity
implements ColorPickerDialog.OnColorChangedListener {
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
Button b;
Dialog dialog;
static MyView mv;
File f;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout ll = (LinearLayout) findViewById(R.id.ll);
mv= new MyView(this);
mv.setDrawingCacheEnabled(true);
ll.addView(mv);
b= (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
final CharSequence[] items = {"Pick Color", "Emboss", "Blur","Erase","SaveToGallery"};
AlertDialog.Builder builder = new AlertDialog.Builder(FingerPaintActivity.this);
builder.setTitle("Options");
builder.setItems(items, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {
if(item==0)
{
new ColorPickerDialog(FingerPaintActivity.this, FingerPaintActivity.this, mPaint.getColor()).show();
}
if(item==1)
{
if (mPaint.getMaskFilter() != mEmboss) {
mPaint.setMaskFilter(mEmboss);
} else {
mPaint.setMaskFilter(null);
}
}
if(item==2)
{
if (mPaint.getMaskFilter() != mBlur) {
mPaint.setMaskFilter(mBlur);
} else {
mPaint.setMaskFilter(null);
}
}
if(item==3)
{
mPaint.setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.CLEAR));
}
if(item==4)
{
saveImage();
}
}
});
builder.show();
}
});
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(20);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
public void colorChanged(int color) {
mPaint.setColor(color);
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
Context mcontext;
public MyView(Context c) {
super(c);
mcontext=c;
mPath = new Path();
mBitmapPaint = new Paint();
mBitmapPaint.setColor(Color.RED);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(0xFFAAAAAA);
Display display = ( (Activity) mcontext).getWindowManager().getDefaultDisplay();
float w = display.getWidth();
float h = display.getHeight();
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawLine(0, 0, w, 0,mBitmapPaint);
canvas.drawLine(0, 0, 0, h,mBitmapPaint);
canvas.drawLine(w,h,w,0,mBitmapPaint);
canvas.drawLine(w, h, 0,h , 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);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SCREEN));
// 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 void saveImage()
{
AlertDialog.Builder editalert = new AlertDialog.Builder(FingerPaintActivity.this);
editalert.setTitle("Please Enter the name with which you want to Save");
final EditText input = new EditText(FingerPaintActivity.this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.FILL_PARENT);
input.setLayoutParams(lp);
editalert.setView(input);
editalert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
mv.setDrawingCacheEnabled(true);
String name= input.getText().toString();
Bitmap bitmap = mv.getDrawingCache();
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/MapleBearDraw");
myDir.mkdirs();
File file = new File (myDir, name+".jpg");
if (file.exists ()) file.delete ();
try
{
if(!file.exists())
{
file.createNewFile();
}
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(CompressFormat.JPEG, 50, ostream);
ostream.flush();
ostream.close();
mv.invalidate();
}
catch (Exception e)
{
e.printStackTrace();
}finally
{
mv.setDrawingCacheEnabled(false);
}
}
});
editalert.show();
}
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;
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
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 COLOR_MENU_ID:
new ColorPickerDialog(FingerPaintActivity.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);
}
}