Finger Paint : Paint « 2D Graphics « Android






Finger Paint

  
/*
 * 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 app.test;

import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorMatrix;
import android.graphics.EmbossMaskFilter;
import android.graphics.MaskFilter;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Picture;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.SweepGradient;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;

public class Test extends GraphicsActivity implements
    ColorPickerDialog.OnColorChangedListener {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new MyView(this));

    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);
  }

  private Paint mPaint;
  private MaskFilter mEmboss;
  private MaskFilter mBlur;

  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;

    public MyView(Context c) {
      super(c);

      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);
      mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
      mCanvas = new Canvas(mBitmap);
    }

    @Override
    protected void onDraw(Canvas canvas) {
      canvas.drawColor(0xFFAAAAAA);

      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;
    }
  }

  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;

  @Override
  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(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);
  }
}

class ColorPickerDialog extends Dialog {

  public interface OnColorChangedListener {
    void colorChanged(int color);
  }

  private OnColorChangedListener mListener;
  private int mInitialColor;

  private static class ColorPickerView extends View {
    private Paint mPaint;
    private Paint mCenterPaint;
    private final int[] mColors;
    private OnColorChangedListener mListener;

    ColorPickerView(Context c, OnColorChangedListener l, int color) {
      super(c);
      mListener = l;
      mColors = new int[] { 0xFFFF0000, 0xFFFF00FF, 0xFF0000FF,
          0xFF00FFFF, 0xFF00FF00, 0xFFFFFF00, 0xFFFF0000 };
      Shader s = new SweepGradient(0, 0, mColors, null);

      mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
      mPaint.setShader(s);
      mPaint.setStyle(Paint.Style.STROKE);
      mPaint.setStrokeWidth(32);

      mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
      mCenterPaint.setColor(color);
      mCenterPaint.setStrokeWidth(5);
    }

    private boolean mTrackingCenter;
    private boolean mHighlightCenter;

    @Override
    protected void onDraw(Canvas canvas) {
      float r = CENTER_X - mPaint.getStrokeWidth() * 0.5f;

      canvas.translate(CENTER_X, CENTER_X);

      canvas.drawOval(new RectF(-r, -r, r, r), mPaint);
      canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint);

      if (mTrackingCenter) {
        int c = mCenterPaint.getColor();
        mCenterPaint.setStyle(Paint.Style.STROKE);

        if (mHighlightCenter) {
          mCenterPaint.setAlpha(0xFF);
        } else {
          mCenterPaint.setAlpha(0x80);
        }
        canvas.drawCircle(0, 0,
            CENTER_RADIUS + mCenterPaint.getStrokeWidth(),
            mCenterPaint);

        mCenterPaint.setStyle(Paint.Style.FILL);
        mCenterPaint.setColor(c);
      }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
      setMeasuredDimension(CENTER_X * 2, CENTER_Y * 2);
    }

    private static final int CENTER_X = 100;
    private static final int CENTER_Y = 100;
    private static final int CENTER_RADIUS = 32;

    private int floatToByte(float x) {
      int n = java.lang.Math.round(x);
      return n;
    }

    private int pinToByte(int n) {
      if (n < 0) {
        n = 0;
      } else if (n > 255) {
        n = 255;
      }
      return n;
    }

    private int ave(int s, int d, float p) {
      return s + java.lang.Math.round(p * (d - s));
    }

    private int interpColor(int colors[], float unit) {
      if (unit <= 0) {
        return colors[0];
      }
      if (unit >= 1) {
        return colors[colors.length - 1];
      }

      float p = unit * (colors.length - 1);
      int i = (int) p;
      p -= i;

      // now p is just the fractional part [0...1) and i is the index
      int c0 = colors[i];
      int c1 = colors[i + 1];
      int a = ave(Color.alpha(c0), Color.alpha(c1), p);
      int r = ave(Color.red(c0), Color.red(c1), p);
      int g = ave(Color.green(c0), Color.green(c1), p);
      int b = ave(Color.blue(c0), Color.blue(c1), p);

      return Color.argb(a, r, g, b);
    }

    private int rotateColor(int color, float rad) {
      float deg = rad * 180 / 3.1415927f;
      int r = Color.red(color);
      int g = Color.green(color);
      int b = Color.blue(color);

      ColorMatrix cm = new ColorMatrix();
      ColorMatrix tmp = new ColorMatrix();

      cm.setRGB2YUV();
      tmp.setRotate(0, deg);
      cm.postConcat(tmp);
      tmp.setYUV2RGB();
      cm.postConcat(tmp);

      final float[] a = cm.getArray();

      int ir = floatToByte(a[0] * r + a[1] * g + a[2] * b);
      int ig = floatToByte(a[5] * r + a[6] * g + a[7] * b);
      int ib = floatToByte(a[10] * r + a[11] * g + a[12] * b);

      return Color.argb(Color.alpha(color), pinToByte(ir), pinToByte(ig),
          pinToByte(ib));
    }

    private static final float PI = 3.1415926f;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
      float x = event.getX() - CENTER_X;
      float y = event.getY() - CENTER_Y;
      boolean inCenter = java.lang.Math.sqrt(x * x + y * y) <= CENTER_RADIUS;

      switch (event.getAction()) {
      case MotionEvent.ACTION_DOWN:
        mTrackingCenter = inCenter;
        if (inCenter) {
          mHighlightCenter = true;
          invalidate();
          break;
        }
      case MotionEvent.ACTION_MOVE:
        if (mTrackingCenter) {
          if (mHighlightCenter != inCenter) {
            mHighlightCenter = inCenter;
            invalidate();
          }
        } else {
          float angle = (float) java.lang.Math.atan2(y, x);
          // need to turn angle [-PI ... PI] into unit [0....1]
          float unit = angle / (2 * PI);
          if (unit < 0) {
            unit += 1;
          }
          mCenterPaint.setColor(interpColor(mColors, unit));
          invalidate();
        }
        break;
      case MotionEvent.ACTION_UP:
        if (mTrackingCenter) {
          if (inCenter) {
            mListener.colorChanged(mCenterPaint.getColor());
          }
          mTrackingCenter = false; // so we draw w/o halo
          invalidate();
        }
        break;
      }
      return true;
    }
  }

  public ColorPickerDialog(Context context, OnColorChangedListener listener,
      int initialColor) {
    super(context);

    mListener = listener;
    mInitialColor = initialColor;
  }

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    OnColorChangedListener l = new OnColorChangedListener() {
      public void colorChanged(int color) {
        mListener.colorChanged(color);
        dismiss();
      }
    };

    setContentView(new ColorPickerView(getContext(), l, mInitialColor));
    setTitle("Pick a Color");
  }
}

class GraphicsActivity extends Activity {
  // set to true to test Picture
  private static final boolean TEST_PICTURE = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  }

  @Override
  public void setContentView(View view) {
    if (TEST_PICTURE) {
      ViewGroup vg = new PictureLayout(this);
      vg.addView(view);
      view = vg;
    }

    super.setContentView(view);
  }
}

class PictureLayout extends ViewGroup {
  private final Picture mPicture = new Picture();

  public PictureLayout(Context context) {
    super(context);
  }

  public PictureLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  @Override
  public void addView(View child) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child);
  }

  @Override
  public void addView(View child, int index) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index);
  }

  @Override
  public void addView(View child, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, params);
  }

  @Override
  public void addView(View child, int index, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index, params);
  }

  @Override
  protected LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(LayoutParams.MATCH_PARENT,
        LayoutParams.MATCH_PARENT);
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int count = getChildCount();

    int maxHeight = 0;
    int maxWidth = 0;

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        measureChild(child, widthMeasureSpec, heightMeasureSpec);
      }
    }

    maxWidth += getPaddingLeft() + getPaddingRight();
    maxHeight += getPaddingTop() + getPaddingBottom();

    Drawable drawable = getBackground();
    if (drawable != null) {
      maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
      maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
    }

    setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
        resolveSize(maxHeight, heightMeasureSpec));
  }

  private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
      float sy) {
    canvas.save();
    canvas.translate(x, y);
    canvas.clipRect(0, 0, w, h);
    canvas.scale(0.5f, 0.5f);
    canvas.scale(sx, sy, w, h);
    canvas.drawPicture(mPicture);
    canvas.restore();
  }

  @Override
  protected void dispatchDraw(Canvas canvas) {
    super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
    mPicture.endRecording();

    int x = getWidth() / 2;
    int y = getHeight() / 2;

    if (false) {
      canvas.drawPicture(mPicture);
    } else {
      drawPict(canvas, 0, 0, x, y, 1, 1);
      drawPict(canvas, x, 0, x, y, -1, 1);
      drawPict(canvas, 0, y, x, y, 1, -1);
      drawPict(canvas, x, y, x, y, -1, -1);
    }
  }

  @Override
  public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
    location[0] = getLeft();
    location[1] = getTop();
    dirty.set(0, 0, getWidth(), getHeight());
    return getParent();
  }

  @Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = super.getChildCount();

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        final int childLeft = getPaddingLeft();
        final int childTop = getPaddingTop();
        child.layout(childLeft, childTop,
            childLeft + child.getMeasuredWidth(),
            childTop + child.getMeasuredHeight());

      }
    }
  }
}

   
    
  








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