How to prevent scrolling while drawing inside Scrollview
I have got a drawing View and a ScrollView
with Elements in it. The problem is, that I only could draw lines horizontally, because when I try to draw lines vertically the view is scrolling down because of the ScrollView.
When I delete the ScrollView,
also the vertically lines could draw, but I need the ScrollView
in order to display all the Elements.
I tried to change the overScrollMode
in the ScrollView,
but this didn't help.
How to prevent scrolling down the view, while I draw in drawing View?
Here's the corresponding part of xml
file:
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/openproctScrollview"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="#FFFFFF"
android:fillViewport="true"
android:overScrollMode="never">
<FrameLayout
android:id="@+id/drawingLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.unitnode.Drawing
android:id="@+id/drawingView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="ifContentScrolls" />
</FrameLayout>
</ScrollView>
Here is the drawing class:
public class Drawing extends View {
private static final float TOUCH_TOLERANCE = 4;
public static String strichFarbeHex;
private Path mPath;
private Canvas canvas;
private Paint mPaint;
private Paint mBitmapPaint;
private Bitmap mBitmap;
private BlurMaskFilter mBlur;
private MaskFilter mEmboss;
private float mX, mY;
public Drawing(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setStrokeWidth(12);
mPaint.setStyle(Paint.Style.STROKE);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
this.setDrawingCacheEnabled(true);
mEmboss = new EmbossMaskFilter(new float[]{1, 1, 1}, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
this.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
float x = event.getX();
float y = event.getY();
Log.d("onTouch", "onTouch");
Log.d("x", String.valueOf(x));
Log.d("y", String.valueOf(y));
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
Log.d("a", "down");
Log.d("hier", "hier1");
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
Log.d("onTouch", "onTouch2");
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
Log.d("onTouch", "onTouch3");
touch_up();
invalidate();
break;
}
return true;
}
});
}
// mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
public static String setStrichFarbe(String strichFarbe) {
strichFarbeHex = strichFarbe;
Log.d("strichFarbeHex", "strichFarbeHex " + strichFarbeHex);
return strichFarbeHex;
}
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
canvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
// mPaint.setXfermode(new PorterDuffXfermode(Mode.SCREEN));
// mPaint.setMaskFilter(null);
// mPath.reset();
}
@Override
public void onDraw(Canvas c) {
Log.d("onDraw", "onDraw " + mPath + "|" + mPaint);
long startTime = this.getDrawingTime();
Log.d("startTime", "startTime " + startTime);
mPaint.setColor(Color.WHITE);
c.drawPaint(mPaint);
// TODO: Ändern der Strichfarbe soll nicht komplett alles ändern, sondern nur den letzten Strich
if (strichFarbeHex != null) {
String strichFarbHexCode = getStrichFarbe();
Log.d("strichFarbHexCode", "strichFarbHexCode " + strichFarbHexCode);
mPaint.setColor(Color.parseColor(strichFarbHexCode));
} else {
mPaint.setColor(Color.parseColor("#CD5C5C"));
}
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
c.drawPath(mPath, mPaint);
}
@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);
canvas = new Canvas(mBitmap);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// wenn die Zurücktaste das erste Mal gedrückt wurde
if (keyCode == KeyEvent.KEYCODE_BACK) {
}
return true;
}
public String getStrichFarbe() {
return strichFarbeHex;
}
}
and this picture shows how it looks like:
Thanks for helping
I had the same issue.
Try giving
getParent().requestDisallowInterceptTouchEvent(true);
inside the drawing function.- onDraw(Canvas c)
链接地址: http://www.djcxy.com/p/63698.html下一篇: 如何在滚动视图内绘制时防止滚动