17

現在、webview 画像 (下の象) に描画機能を実装しています。描画に問題はありませんが、ズーム機能により、描画上でいくつかのファンキーな処理が行われます (下の 2 番目の画像)。ズームインすると、図面はズームせずにシフトオーバーします。ズームでの描画も機能しません。私のコードは以下の通りです：

普通

ここに画像の説明を入力

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.save();
    canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
    canvas.drawPath(drawPath, drawPaint);
    canvas.scale(mScaleFactor, mScaleFactor);
    canvas.restore();
    clipBounds = canvas.getClipBounds();
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    mScaleDetector.onTouchEvent(event);
    float touchX = event.getX() / mScaleFactor + clipBounds.left;
    float touchY = event.getY() / mScaleFactor + clipBounds.top;
    if (Deal.on)
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                drawPath.moveTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_MOVE:
                drawPath.lineTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_UP:
                drawCanvas.drawPath(drawPath, drawPaint);
                drawPath.reset();
                break;
            default:
                return false;
    }
    else {
        super.onTouchEvent(event);
    }
    invalidate();
    return true;
}

public class ScaleGestureListener extends SimpleOnScaleGestureListener {
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        mScaleFactor *= detector.getScaleFactor();

        // Don't let the object get too small or too large.
        mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));

        invalidate();

        return true;
    }
}

編集: GestureDetector のスケール ファクターを使用して、ズームでキャンバスを再描画することができました。さらに、描画からズーム/WebView コントロールに切り替えるスイッチがあります。私が遭遇した問題は、WebView をダブルタップしても onScale ジェスチャがトリガーされないことです。つまり、キャンバスは再描画されず、拡大時にシフトします。

ダブルタップのズームインによって倍率がどれだけ影響を受けるかを検出する機能を実装する必要があります。誰かがその解決策を提案できる場合。更新コードは次のとおりです。

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    clipBounds = canvas.getClipBounds();
    canvas.save();
    drawPaint.setStrokeWidth(8/mScaleFactor);
    canvas.scale(mScaleFactor, mScaleFactor, 0, 0);
    canvas.drawPath(drawPath, drawPaint);
    canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
    canvas.restore();
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    pointerCount = event.getPointerCount();
    mScaleDetector.onTouchEvent(event);
    float touchX = (event.getX() + clipBounds.left) / mScaleFactor;
    float touchY = (event.getY() + clipBounds.top) / mScaleFactor;
    if (Deal.on){
        if (event.getPointerCount() > 1){
            return false;
        }
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                drawPath.moveTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_MOVE:
                drawPath.lineTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_UP:
                drawCanvas.drawPath(drawPath, drawPaint);
                drawPath.reset();
                break;
            default:
                return false;
        }
    }
    else {
        super.onTouchEvent(event);
    }
    invalidate();
    return true;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
   // Try for a width based on our minimum
   int minw = getPaddingLeft() + getPaddingRight() + getSuggestedMinimumWidth();
   int w = resolveSizeAndState(minw, widthMeasureSpec, 1);

   //int minh = MeasureSpec.getSize(w) - (int)mTextWidth + getPaddingBottom() + getPaddingTop();
   int h = resolveSizeAndState(MeasureSpec.getSize(w), heightMeasureSpec, 0);
   setMeasuredDimension(w, h);
}

public class ScaleGestureListener extends SimpleOnScaleGestureListener {

    @Override
    public boolean onScale(ScaleGestureDetector detector) {

        // Don't let the object get too small or too large.
        if(Deal.on == false) {
            mScaleFactor *= detector.getScaleFactor();
            mScaleFactor = Math.max(1f, Math.min(mScaleFactor, 20.0f));
        }

        invalidate();

        return true;
    }
}
4

5 に答える 5

0 
check below code will help you.

//CUSTOM IMAGEVIEW
import java.io.ByteArrayOutputStream;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.FloatMath;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;

public class ScaleImageView extends ImageView implements OnTouchListener {

static final float STROKE_WIDTH = 10f;
static final float HALF_STROKE_WIDTH = STROKE_WIDTH / 2;

float lastTouchX;
float lastTouchY;
final RectF dirtyRect = new RectF();

private Context mContext;
private float MAX_SCALE = 2f;

private static Matrix mMatrix;
private final float[] mMatrixValues = new float[9];

// display width height.
private int mWidth;
private int mHeight;

private int mIntrinsicWidth;
private int mIntrinsicHeight;

private float mScale;
private float mMinScale;

private float mPrevDistance;
private boolean isScaling;

private int mPrevMoveX;
private int mPrevMoveY;
private GestureDetector mDetector;

Paint paint = new Paint();
public static Path path = new Path();

public static int imageheight, imagewidth;

String TAG = "ScaleImageView";

public ScaleImageView(Context context, AttributeSet attr) {
super(context, attr);
this.mContext = context;
initialize();
}

public ScaleImageView(Context context) {
super(context);
this.mContext = context;
initialize();
}

private void resetDirtyRect(float eventX, float eventY) {
dirtyRect.left = Math.min(lastTouchX, eventX);
dirtyRect.right = Math.max(lastTouchX, eventX);
dirtyRect.top = Math.min(lastTouchY, eventY);
dirtyRect.bottom = Math.max(lastTouchY, eventY);
}

@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
this.initialize();
}

@Override
public void setImageResource(int resId) {
super.setImageResource(resId);
this.initialize();
}

private void initialize() {
this.setScaleType(ScaleType.MATRIX);
this.mMatrix = new Matrix();
Drawable d = getDrawable();

paint.setAntiAlias(true);
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);

if (d != null) {
    mIntrinsicWidth = d.getIntrinsicWidth();
    mIntrinsicHeight = d.getIntrinsicHeight();
    setOnTouchListener(this);
}
mDetector = new GestureDetector(mContext,
        new GestureDetector.SimpleOnGestureListener() {
            @Override
            public boolean onDoubleTap(MotionEvent e) {
                maxZoomTo((int) e.getX(), (int) e.getY());
                cutting();
                return super.onDoubleTap(e);
            }
        });

}

@Override
protected boolean setFrame(int l, int t, int r, int b) {
mWidth = r - l;
mHeight = b - t;

mMatrix.reset();
int r_norm = r - l;
mScale = (float) r_norm / (float) mIntrinsicWidth;

int paddingHeight = 0;
int paddingWidth = 0;
// scaling vertical
if (mScale * mIntrinsicHeight > mHeight) {
    mScale = (float) mHeight / (float) mIntrinsicHeight;
    mMatrix.postScale(mScale, mScale);
    paddingWidth = (r - mWidth) / 2;
    paddingHeight = 0;
    // scaling horizontal
} else {
    mMatrix.postScale(mScale, mScale);
    paddingHeight = (b - mHeight) / 2;
    paddingWidth = 0;
}
mMatrix.postTranslate(paddingWidth, paddingHeight);

setImageMatrix(mMatrix);
mMinScale = mScale;
zoomTo(mScale, mWidth / 2, mHeight / 2);
cutting();
return super.setFrame(l, t, r, b);
}

protected float getValue(Matrix matrix, int whichValue) {
matrix.getValues(mMatrixValues);
return mMatrixValues[whichValue];
}

protected float getScale() {
return getValue(mMatrix, Matrix.MSCALE_X);
}

public float getTranslateX() {
return getValue(mMatrix, Matrix.MTRANS_X);
}

protected float getTranslateY() {
return getValue(mMatrix, Matrix.MTRANS_Y);
}

protected void maxZoomTo(int x, int y) {
if (mMinScale != getScale() && (getScale() - mMinScale) > 0.1f) {
    // threshold 0.1f
    float scale = mMinScale / getScale();
    zoomTo(scale, x, y);
} else {
    float scale = MAX_SCALE / getScale();
    zoomTo(scale, x, y);
}
}

public void zoomTo(float scale, int x, int y) {
if (getScale() * scale < mMinScale) {
    return;
}
if (scale >= 1 && getScale() * scale > MAX_SCALE) {
    return;
}
mMatrix.postScale(scale, scale);
// move to center
mMatrix.postTranslate(-(mWidth * scale - mWidth) / 2,
        -(mHeight * scale - mHeight) / 2);

// move x and y distance
mMatrix.postTranslate(-(x - (mWidth / 2)) * scale, 0);
mMatrix.postTranslate(0, -(y - (mHeight / 2)) * scale);
setImageMatrix(mMatrix);
}

public void cutting() {
int width = (int) (mIntrinsicWidth * getScale());
int height = (int) (mIntrinsicHeight * getScale());

imagewidth = width;
imageheight = height;

if (getTranslateX() < -(width - mWidth)) {
    mMatrix.postTranslate(-(getTranslateX() + width - mWidth), 0);
}
if (getTranslateX() > 0) {
    mMatrix.postTranslate(-getTranslateX(), 0);
}
if (getTranslateY() < -(height - mHeight)) {
    mMatrix.postTranslate(0, -(getTranslateY() + height - mHeight));
}
if (getTranslateY() > 0) {
    mMatrix.postTranslate(0, -getTranslateY());
}
if (width < mWidth) {
    mMatrix.postTranslate((mWidth - width) / 2, 0);
}
if (height < mHeight) {
    mMatrix.postTranslate(0, (mHeight - height) / 2);
}
setImageMatrix(mMatrix);
}

private float distance(float x0, float x1, float y0, float y1) {
float x = x0 - x1;
float y = y0 - y1;
return FloatMath.sqrt(x * x + y * y);
}

private float dispDistance() {
return FloatMath.sqrt(mWidth * mWidth + mHeight * mHeight);
}

public void clear() {
path.reset();
invalidate();
}

public static void save() {

Bitmap returnedBitmap = Bitmap.createBitmap(
        ScaleImageViewActivity.imageview.getWidth(),
        ScaleImageViewActivity.imageview.getHeight(),
        Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);

Drawable bgDrawable = ScaleImageViewActivity.imageview.getDrawable();

if (bgDrawable != null)
    bgDrawable.draw(canvas);
else
    canvas.drawColor(Color.WHITE);

ScaleImageViewActivity.imageview.draw(canvas);

ByteArrayOutputStream bs = new ByteArrayOutputStream();
returnedBitmap.compress(Bitmap.CompressFormat.PNG, 50, bs);

Bitmap FinalBitmap = BitmapFactory.decodeByteArray(bs.toByteArray(), 0,
        bs.toByteArray().length);

ScaleImageViewActivity.imageview.setImageBitmap(FinalBitmap);
path.reset();

// ScaleImageViewActivity.imageview.setImageMatrix(mMatrix);

}

@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
if (!ScaleImageViewActivity.flag) {

    if (mDetector.onTouchEvent(event)) {
        return true;
    }
    int touchCount = event.getPointerCount();
    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
    case MotionEvent.ACTION_POINTER_1_DOWN:
    case MotionEvent.ACTION_POINTER_2_DOWN:
        if (touchCount >= 2) {
            float distance = distance(event.getX(0), event.getX(1),
                    event.getY(0), event.getY(1));
            mPrevDistance = distance;
            isScaling = true;
        } else {
            mPrevMoveX = (int) event.getX();
            mPrevMoveY = (int) event.getY();
        }
    case MotionEvent.ACTION_MOVE:
        if (touchCount >= 2 && isScaling) {
            float dist = distance(event.getX(0), event.getX(1),
                    event.getY(0), event.getY(1));
            float scale = (dist - mPrevDistance) / dispDistance();
            mPrevDistance = dist;
            scale += 1;
            scale = scale * scale;
            zoomTo(scale, mWidth / 2, mHeight / 2);
            cutting();
        } else if (!isScaling) {
            int distanceX = mPrevMoveX - (int) event.getX();
            int distanceY = mPrevMoveY - (int) event.getY();
            mPrevMoveX = (int) event.getX();
            mPrevMoveY = (int) event.getY();
            mMatrix.postTranslate(-distanceX, -distanceY);
            cutting();
        }
        break;
    case MotionEvent.ACTION_UP:
    case MotionEvent.ACTION_POINTER_UP:
    case MotionEvent.ACTION_POINTER_2_UP:
        if (event.getPointerCount() <= 1) {
            isScaling = false;
        }
        break;
    }
} else {
    float eventX = event.getX();
    float eventY = event.getY();

    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
        path.moveTo(eventX, eventY);
        lastTouchX = eventX;
        lastTouchY = eventY;
        return true;

    case MotionEvent.ACTION_MOVE:

    case MotionEvent.ACTION_UP:

        resetDirtyRect(eventX, eventY);
        int historySize = event.getHistorySize();
        for (int i = 0; i < historySize; i++) {
            float historicalX = event.getHistoricalX(i);
            float historicalY = event.getHistoricalY(i);
            path.lineTo(historicalX, historicalY);
        }
        path.lineTo(eventX, eventY);
        break;
    }

    invalidate((int) (dirtyRect.left - HALF_STROKE_WIDTH),
            (int) (dirtyRect.top - HALF_STROKE_WIDTH),
            (int) (dirtyRect.right + HALF_STROKE_WIDTH),
            (int) (dirtyRect.bottom + HALF_STROKE_WIDTH));

    lastTouchX = eventX;
    lastTouchY = eventY;
}
return true;
}

@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
if (ScaleImageViewActivity.flag)
    canvas.drawPath(path, paint);
}

@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouch(View v, MotionEvent event) {
return super.onTouchEvent(event);
}

}

//ACTIVITY

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class ScaleImageViewActivity extends Activity implements OnClickListener {

Button btndraw, btnzoom, btnsave;

public static ScaleImageView imageview;
public static boolean flag = true;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initwidget();
}

private void initwidget() {

imageview = (ScaleImageView) findViewById(R.id.image);

btnsave = (Button) findViewById(R.id.activity_main_save);
btndraw = (Button) findViewById(R.id.activity_main_zoom_draw);
btnzoom = (Button) findViewById(R.id.activity_main_zoom_zoom);

btndraw.setOnClickListener(this);
btnzoom.setOnClickListener(this);
btnsave.setOnClickListener(this);
}

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if (btndraw.equals(arg0)) {
    flag = true;
} else if (btnzoom.equals(arg0)) {
    flag = false;
} else if (btnsave.equals(arg0)) {
    ScaleImageView.save();
}
}
}
main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >

<Button
    android:id="@+id/activity_main_zoom_zoom"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Zoom" />

<Button
    android:id="@+id/activity_main_zoom_draw"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Draw" />

<Button
    android:id="@+id/activity_main_save"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Save" />
</LinearLayout>

<com.matabii.dev.scaleimageview.ScaleImageView
android:id="@+id/image"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/sample" />

</LinearLayout>
于 2014-11-19T07:47:41.763 に答える
0

パスを一度だけ描画して、キャンバス自体の責任でズームを維持できますか

private boolean pathsDrawn;

protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    clipBounds = canvas.getClipBounds();
    canvas.save();
    drawPaint.setStrokeWidth(8/mScaleFactor);
    canvas.scale(mScaleFactor, mScaleFactor, 0, 0);

    if(!pathsDrawn) {
       canvas.drawPath(drawPath, drawPaint);
       pathsDrawn = true;
    }
    canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
    canvas.restore();
}
于 2013-10-27T11:32:37.213 に答える
0

このチュートリアルを見てください。ここでは、2 つの Matrix オブジェクトを使用して、翻訳とスケーリングを管理しています。マトリックスを使用することをお勧めします。そうしないと、新しい座標を計算するのが面倒で面倒になる可能性があります。あなたの問題は、翻訳を正しく管理していないことが原因です。注: チュートリアルでは、OnDraw() 内で、 が抜けておりcanvas.concat(matrix)、直後に配置しますcanvas.drawBitmap(...)

于 2018-10-30T17:00:22.723 に答える