LogoView.java

/*
 * Copyright 2015 Daniel Dittmar
 *
 * 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 dan.dit.whatsthat.image;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;

import dan.dit.whatsthat.R;
import dan.dit.whatsthat.preferences.User;
import dan.dit.whatsthat.util.image.ImageUtil;

/**
 * Created by daniel on 13.10.15.
 */
public class LogoView extends View {

    private Path mPath;
    private Paint mBitmapPaint;
    private Paint mCirclePaint;
    private Path mCirclePath;
    private Bitmap mBitmap;
    private Canvas mCanvas;
    private Paint mPaint;
    private Paint mClearPaint;
    private boolean mChanged;

    public LogoView(Context context) {
        super(context);
        init();
    }

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

    private void init() {
        setWillNotDraw(false);
        mClearPaint = new Paint();
        mClearPaint.setColor(Color.WHITE);
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setDither(true);
        mPaint.setColor(Color.BLACK);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(15);

        mPath = new Path();
        mBitmapPaint = new Paint(Paint.DITHER_FLAG);
        mCirclePaint = new Paint();
        mCirclePath = new Path();
        mCirclePaint.setAntiAlias(true);
        mCirclePaint.setColor(Color.DKGRAY);
        mCirclePaint.setStyle(Paint.Style.STROKE);
        mCirclePaint.setStrokeJoin(Paint.Join.MITER);
        mCirclePaint.setStrokeWidth(4f);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        initFromLogo();
    }

    private void initFromLogo() {
        Logo logo = User.getInstance().getLogo(getResources());
        mBitmap = logo.getSized(getWidth(), getHeight());
        mCanvas = new Canvas(mBitmap);
        mChanged = false;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
        canvas.drawPath(mPath, mPaint);
        canvas.drawPath( mCirclePath,  mCirclePaint);
    }

    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;

            mCirclePath.reset();
            mCirclePath.addCircle(mX, mY, 30, Path.Direction.CW);
        }
    }

    private void touch_up() {
        mPath.lineTo(mX, mY);
        mCirclePath.reset();
        // commit the path to our offscreen
        mCanvas.drawPath(mPath,  mPaint);
        // kill this so we don't double draw
        mPath.reset();
        mChanged = true;
    }

    @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 onRedo() {
        if (mChanged) {
            initFromLogo();
        } else {
            mCanvas.drawPaint(mClearPaint);
        }
        invalidate();
    }

    public void onSave() {
        if (ImageUtil.saveToFile(mBitmap, User.getLogoFile(), Bitmap.CompressFormat.PNG, 100)) {
            Toast.makeText(getContext(), R.string.logo_saved, Toast.LENGTH_SHORT).show();
        }
    }
}