almeros / android-gesture-detectors Goto Github PK

The deprecated class has been removed.

"Historically these methods were faster than the equivalent double-based Math methods. On versions of Android with a JIT they became slower and have since been re-implemented to wrap calls to Math. Math should be used in preference.
All methods were removed from the public API in version 23."

http://developer.android.com/reference/android/util/FloatMath.html

The library now needs to use eg. (float) Math.sqrt(pvx_pvx + pvy_pvy);

If I created Two ImageView instances in Single Activity and Attach Separate Instances of Rotation Gesture Detector to them the Only Rotation Listener for First ImageView Is Working Second Image's Rotation Gestures are not being able to detect .Please provide some solution to that its been 8 hours I am searching for solution.

Thanks.

I'm struggling a bit to get this to work as expected with a dynamically created TextView (or any View other than the ImageView). For the 'move' detector, the TextView appears to be 'lagging' behind my finger. Two finger gestures cause the view to 'split' in two until I let go of one of the fingers.

Any help on figuring this out would be much appreciated. (I've also tried using Matrix transformations with the TextView by overriding OnDraw, but had little luck with that as well).

Here's the modification from the Sample (View instantiation not shown):

public boolean onTouch(View v, MotionEvent event)
    {
        mScaleDetector.onTouchEvent(event);
        mRotateDetector.onTouchEvent(event);
        mMoveDetector.onTouchEvent(event);
        mShoveDetector.onTouchEvent(event);

        float scaledViewCenterX = (_originalWidth * mScaleFactor)/2;
        float scaledViewCenterY = (_originalHeight * mScaleFactor) /2;

        // also attempted to translate with the difference to no avail
        //float diffX = mFocusX - scaledViewCenterX;
        //float diffY = mFocusY - scaledViewCenterY;
        //v.setTranslationX(diffX*mScaleFactor);
        //v.setTranslationY(diffY*mScaleFactor);

        // Scale : Splits view in two. Jitters
        v.setScaleX(mScaleFactor);
        v.setScaleY(mScaleFactor);

        // Translate : Lags behind finger. Jitters
        v.setX(mFocusX);
        v.setY(mFocusY);

        // Set pivot joint
        v.setPivotX(scaledViewCenterX);
        v.setPivotY(scaledViewCenterY);

        // Rotate : Splits view in two. Jitters
        v.setRotation(mRotationDegrees);
}

Performing minuscule rotations while having rotation line between fingers horizontal causes to getRotationDegreesDelta to output values close to 360, e.g. -359.4 or 359.2.

This is caused by Math.atan2 used to calculate diff angle having ambiguity around +-180*. All is fine and well when performed rotation is shown 1:1 on screen, but I'm scaling it to get more precise moment with small values, so when the received values are 0.015, 0.020, 0.017, -359.4, 0.021... it causes a sudden jerk.

IMO it's a bug because nobody expects sudden 360 for minuscule finger motion when calling getRotationDegreesDelta. The real change of angle is certainly NOT a 360 degree.

My workaround was:

val raw = detector.rotationDegreesDelta
val diffRotation = if (abs(raw) > 300) {   // or some other arbitrary value above 180*
    if (raw < 0) {
        360 + raw
    } else {
        raw - 360
    }
} else raw

I think better fix (without arbitrary 300* value) can be done on library side by checking if one angle falls close to 180* and other close to -180*, so it's passing through discontinous part of Math.atan2 and can be accounted for.

This gesture detector example is very helpful, but it appears to always zoom relative to the center of the image, which may be well outside the currently displayed area. Would it be possible to zoom about the center of the two touch positions instead? If so, how? Thanks.

Hey @Almeros, thanks for your work here, we're big fans of this library and we use it extensively as part of our SDK https://github.com/mapbox/mapbox-gl-native. I'd love to chat with you about a few ideas we have for the project. Any chance, you can drop me a line to [email protected]?

Thanks and cc'ing @rharter whom I've also been in touch with.

(Feel free to close this ticket, I just didn't know the best way to reach out.)

We are getting this crash in the TwoFingerGestureDetector.

Fatal Exception: java.lang.IllegalArgumentException: pointerIndex out of range
       at android.view.MotionEvent.nativeGetAxisValue(MotionEvent.java)
       at android.view.MotionEvent.getX(MotionEvent.java:2379)
       at com.almeros.android.multitouch.TwoFingerGestureDetector.updateStateByEvent(TwoFingerGestureDetector.java:77)
       at com.almeros.android.multitouch.RotateGestureDetector.handleInProgressEvent(RotateGestureDetector.java:136)
       at com.almeros.android.multitouch.BaseGestureDetector.onTouchEvent(BaseGestureDetector.java:66)

I'm not sure what it means. Can anyone please help with this?
I've found this one:
https://tldrlegal.com/license/bsd-2-clause-license-(freebsd)

As English isn't my main language, I couldn't understand its meaning, even though I've read in multiple websites (including Wikipedia).

1. What does "Hold Liable" mean? that the original creator of the library won't be charged for damages?
2. What does " Include Copyright" mean? that the app must show the description of the license somewhere within (like the "about" screen or something) ? or just the code should have it ?
   If just the code, what's the difference between it and Apache2 license ?

3.What about derivatives? What if I wish to fork the library? should it also be BSD 2-clause licensed ?

What should and what shouldn't I do?

Hello,

I would like to use this library and handle and resize, rotate, and scale multiple imageviews but without matrix technic. Instead, I would like to user setX, setY, setRotation for example.
Problem is that I'm unable to combine the gestures together.
Do you have an example for this case ?
Thanks

David

Can i detect double tap on it?

Is it possible to upload them in maven central please?

Suppose I want to handle more gestures, that are defined by GestureDetectorCompat , like single tap and double tap, what should I do to handle both those and the ones of the library?

As title says, I cannot detect rotation focus point (the point between the two finger) while rotating. This can be useful to set rotation pivot when user should rotate some object on the screen.

The Android SDK's ScaleGestureDetector gives that focus point, so I can use it to set the "center" of zoom in/out actions.

deletedSelectedEntity() removes the entity from the List entities and even recycles the bitmap but the layer of the entity (to be deleted) still retains on the MotionView and we keep on getting a warning Called getWidth() on a recycle()'d bitmap! This is undefined behaviour!

How can i achieve that if the rotate event is currently active then scale should not happen and when scale event is currently active then rotate should not happen?

Hello

i have been trying to implement both rotating and moving layout , but it doesn't seem to work

when i disable move gesture detector rotation gesture detector works fine , the same thing with scale detector

Not sure what I've done to do it, other than playing with it.

This is what I got in the logs:

java.lang.IllegalArgumentException: pointerIndex out of range
at android.view.MotionEvent.nativeGetAxisValue(Native Method)
at android.view.MotionEvent.getX(MotionEvent.java:1983)
at com.almeros.android.multitouch.TwoFingerGestureDetector.updateStateByEvent(TwoFingerGestureDetector.java:77)
at com.almeros.android.multitouch.RotateGestureDetector.handleInProgressEvent(RotateGestureDetector.java:136)
at com.almeros.android.multitouch.BaseGestureDetector.onTouchEvent(BaseGestureDetector.java:66)

It seems there is a mistake in calculating raw coordinates of motion events, please see TwoFingerGestureDetector.getRawX(MotionEvent, int) (line 122) and TwoFingerGestureDetector.getRawY(MotionEvent, int) (line 136).

You should actually calculate offset like
float offset = event.getRawX() - event.getX();
and
float offset = event.getRawY() - event.getY();

Hello
How can I implement ShoveGestureDetector but detecting horizontal swipe gesture?

TIA!

Hello,

I use: compile 'com.almeros.android-gesture-detectors:library:1.0' in gradle and get "failed to resolve"

can you please help me fix that?

Thank you

hi Almeros, I wondered if i could contact you about working on a project related to your code here, is that possible, i dont see any contact info for you on github. Regards David

It may cause npe in some case.

After double tap to zoom it throws NullPointerException.

java.lang.NullPointerException
            at com.almeros.android.multitouch.BaseGestureDetector.updateStateByEvent(BaseGestureDetector.java:102)
            at com.almeros.android.multitouch.MoveGestureDetector.updateStateByEvent(MoveGestureDetector.java:122)
            at com.almeros.android.multitouch.MoveGestureDetector.handleInProgressEvent(MoveGestureDetector.java:105)
            at com.almeros.android.multitouch.BaseGestureDetector.onTouchEvent(BaseGestureDetector.java:66)

In the following method final MotionEvent prev variable is null.

protected void updateStateByEvent(MotionEvent curr){
        final MotionEvent prev = mPrevEvent;

        // Reset mCurrEvent
        if (mCurrEvent != null) {
            mCurrEvent.recycle();
            mCurrEvent = null;
        }
        mCurrEvent = MotionEvent.obtain(curr);


        // Delta time
        mTimeDelta = curr.getEventTime() - prev.getEventTime();

        // Pressure
        mCurrPressure = curr.getPressure(curr.getActionIndex());
        mPrevPressure = prev.getPressure(prev.getActionIndex());
}

Rare but often bug which is crash app

Fatal Exception: java.lang.IllegalArgumentException: pointerIndex out of range
at android.view.MotionEvent.nativeGetAxisValue(MotionEvent.java)
at android.view.MotionEvent.getX(MotionEvent.java:2136)
at com.rahul.mystickers.multitouch.TwoFingerGestureDetector.updateStateByEvent(TwoFingerGestureDetector.java:76)
at com.rahul.mystickers.multitouch.RotateGestureDetector.handleInProgressEvent(RotateGestureDetector.java:138)
at com.rahul.mystickers.multitouch.BaseGestureDetector.handleInProgressEvent(BaseGestureDetector.java:4)
at com.rahul.mystickers.multitouch.BaseGestureDetector.onTouchEvent(BaseGestureDetector.java:66)

when use in a view which not fixed in Screen, it always tremble.

I use this:
imageView.setRotation(deltaDegree);