mouseReleased in ofxGui

beginners
#1

Is there a way to find out if the mouse has been released after having changed something in ofxGui. I don’t want to know when a specific parameter has changed just whether any parameter has changed and only after the mouse is released (otherwise the program will crash with too much drawing required).

Peter Mc

#2

Hmm. Good thought. I could make use of this as well. I’ve found that the standard mouseReleased functions will only trigger when NOT clicking on an ofParameter (header or group name, for example).

#3

An example where this would be useful:

a video player with an ofxFloatSlider that indicates the current playback time, and allows jumping to any time in the video by clicking on the control.

//.h
ofxFloatSlider time;

//.cpp
void ofApp::setup() {
...
    gui.add(time.setup("time", 0, 0, video.getDuration()));
...
}
void ofApp::update() {
    time = video.getPosition() * video.getDuration();
}

shows the time correctly, but how could I make it jump to a new position on the movie when clicking?

If I add

void ofApp::setup() {
    time.addListener(this, &ofApp::onTimeChanged);
}

the onTimeChanged function is called each time I change time inside update (30 or 60 fps), not just when I click on the gui, so I can’t use that event to call video.setPosition(...).

ofxBaseGui.h has the following:

                virtual bool mouseMoved(ofMouseEventArgs & args) = 0;
                virtual bool mousePressed(ofMouseEventArgs & args) = 0;
                virtual bool mouseDragged(ofMouseEventArgs & args) = 0;
                virtual bool mouseReleased(ofMouseEventArgs & args) = 0;
                virtual bool mouseScrolled(ofMouseEventArgs & args) = 0;
                virtual void mouseEntered(ofMouseEventArgs &){}
                virtual void mouseExited(ofMouseEventArgs &){}

Can we tap into them to detect when the mouse is released on a specific gui item?

#4

the easiest way to do this is to use ofParameter instead of directly the slider:

ofParameter<float> time;


//.cpp
void ofApp::setup() {
...
    gui.add(time.set("time", 0, 0, video.getDuration()));
    time.addListener(this, &ofApp::onTimeChanged);
...
}
void ofApp::update() {
    time.setWithoutEventNotifications(video.getPosition() * video.getDuration());
}
1 Like
#5

Thank you, that sounds like what I need!

But I noticed that then the GUI (the “progress bar”) does not get updated unless I drag the panel around. Maybe the GUI needs the notification to update the component?

#6

oh yeah didn’t realize the gui also relies on the events to update the visualization. you can just set a flag whenever updating the time through code and return right away from the callback that sets the position like:

ofParameter<float> time;
bool settingTime;

//.cpp
void ofApp::setup() {
...
    gui.add(time.set("time", 0, 0, video.getDuration()));
    time.addListener(this, &ofApp::onTimeChanged);
...
}

void ofApp::update() {
    settingTime = true;
    time = video.getPosition() * video.getDuration();
    settingTime = false;
}

void ofApp::onTimeChange(float & t){
    if(settingTime) return;
    ....
}
1 Like