How to add a mouse event in a child class

solub

Following this thread I'm trying to add a mouse event to a sketch using the toxiclibs library.

I'd like to be able to move a specific particle with the mouse and see the distortion on the springs grid.

Here's what the sketch looks like

https://imgur.com/a/vUSd1

Main .Pyde file

add_library('verletphysics')
add_library('toxiclibscore')
from toxi.physics2d import VerletPhysics2D
from toxi.physics2d.behaviors import GravityBehavior 
from Particle import particle
from Locker import locker

def setup():
    size(600, 600, OPENGL)
    smooth(10)
    global physics, collection, lockers, n_rowcol

    physics = VerletPhysics2D()
    physics.addBehavior(GravityBehavior(Vec2D(0, 1)))

    collection, springs, lockers  = [], [], []
    n_rowcol, lngth, strength = 40, 10, .6

    #Display particles and add to Physics
    [[collection.append(particle(100 + (e * 10), 10 + (f * 10))) for f in range(n_rowcol)] for e in range(n_rowcol)]
    [physics.addParticle(e) for e in collection]

    #Lock specific particles
    [collection[e].lock() for e in (0, n_rowcol - 1, n_rowcol ** 2 - n_rowcol, n_rowcol ** 2 - 1)]

    #Display springs
    for e in range(0, n_rowcol ** 2 , n_rowcol):
        for f in range(n_rowcol - 1):
            a = collection[e + f]
            b = collection[e + f + 1]
            s = VerletSpring2D(a, b, lngth, strength)
            physics.addSpring(s)

    for e in range(n_rowcol):
        for f in range(0, n_rowcol ** 2 - n_rowcol, n_rowcol):
            a = collection[e + f]
            b = collection[e + f + n_rowcol]
            s = VerletSpring2D(a, b, lngth, strength)
            physics.addSpring(s)

    #Display lockers (red circles to move with mouse) 
    for e in (0, n_rowcol - 1, n_rowcol ** 2 - n_rowcol, n_rowcol**2 - 1):
        lockers.append(locker(collection[e].x(), collection[e].y()))


def draw():
    background(0)

    #Framerate
    [fill(255), text(int(frameRate), 10, 20)]

    #Run physics
    physics.update()

    #Draw lockers (red circles, not lockers really)
    for e in lockers:
        e.display()
        e.mousePressed()
        e.mouseDragged()

    #Draw particles
    [e.display() for e in collection]

    #Draw springlines
    springlines()


def springlines():
    for e in range(0, n_rowcol ** 2, n_rowcol):
        for f in range(n_rowcol - 1):
            a = collection[e + f]
            b = collection[e + f + 1]
            stroke(255)
            line(a.x(), a.y(), b.x(), b.y())

    for e in range(n_rowcol):
        for f in range(0, n_rowcol ** 2 - n_rowcol, n_rowcol):
            a = collection[e + f]
            b = collection[e + f + n_rowcol]
            stroke(255)
            line(a.x(), a.y(), b.x(), b.y())

Locker.py file

    class locker(object):

        def __init__(self, x, y):
            self.x = x
            self.y = y
            self.over = False
            self.locked = False

        def display(self):

            if dist(self.x, self.y, mouseX, mouseY) < 20:
                self.over = True
                fill(0, 0, 255)
            else:
                self.over = False
                fill(255, 20, 20)
            noStroke()
            ellipse(self.x, self.y, 20, 20)

        def mousePressed(self):
            if mousePressed and self.over:
                self.locked = True
            else:
                self.locked = False

        def mouseDragged(self):
            if self.locked:
                self.x = mouseX
                self.y = mouseY

Particle.py file

    from toxi.physics2d import VerletParticle2D

    class particle(VerletParticle2D):

       over = False

        def display(pos):
            if dist(pos.x(), pos.y(), mouseX, mouseY) < 4:
                pos.over = True
                fill(255, 20, 20)
            else:
                pos.over = False
                fill(255)

            ellipse(pos.x(), pos.y(), 4, 4)

The problem lies in the last snippet above (Particle.py):

To drag a specific particle when mousePressed, I need to access the x and y coordinates of the ellipse (the particle) and say something like:

    def mousePressed(): 
        if pos.over:
            pos.x() = mouseX
            pos.y() = mouseY

But doing so gives me an error: "can't assign to function call" because x() and y() appear as functions.

How can I access the x and y coordinates and make that mouse event work ?

GoToLoop

...because x() and y() appear as functions.

B/c they're indeed getter methods. If you wanna set their values, use the set() method. *-:)

GoToLoop

• There are some further issues in your class particle though. :-S
• 1st 1 is you're using the lowerCamelCase naming convention particle instead of the UpperCamelCase 1 Particle. /:)
• 2nd 1 is that you've created a static variable over instead of an instance variable! #-o
• If you need to have extra instance variables for your subclasses, beyond those automatically inherited by their parent class, you're gonna need to implement __init__()! #:-S
• Take a look at my own class Particle from your previous forum thread: O:-)
  https://Forum.Processing.org/two/discussion/26346/class-inheritance-with-toxiclibs-pyhton#Item_18
• Specifically the commented out: # def __init__(p, *args): super(Particle, p).__init__(*args).
• Here's how to include over as an instance variable member for class Particle: :ar!

def __init__(p, *args, **kw):
    super(Particle, p).__init__(*args, **kw)
    p.over = False

solub

I see... so many things I didn't know. :-B

Following your instructions and this tutorial I came up with this:

from toxi.physics2d import VerletParticle2D

class Particle(VerletParticle2D):

    def __init__(p, over, target):
        super(Particle, p).__init__(over, target)
        p.over = False
        p.target = False

    def display(p):
        if dist(p.x(), p.y(), mouseX, mouseY) < 4:
            p.over = True
            fill(255, 20, 20)
        else:
            p.over = False
            fill(255)

        ellipse(p.x(), p.y(), 4, 4)

    def mousePressed(p):
        if p.over:
            p.target = True
        else:
            p.target = False

    def mouseDragged(p):
        if p.target:
            p.set(mouseX, mouseY)

But unfortunately it's not working properly, the mouse barely drag anything + the mousePressed function doesn't work (the drag function "kind of" works although I didn't press anything). :-?

solub

Also I have carefully looked at your code but please keep in mind that I don't have your level of coding + you integrated many functions that were not really necessary to understand the problem (confusing at first). It's sometime better to focus only on what really matters to convey your idea rather than implementing "subsidiary" functions even though I totally understand the satisfaction to write comprehensive and "pretty" code.

GoToLoop

Callbacks like mousePressed(), mouseDragged(), etc., just like the main 1s setup() & draw(), all of them belong to class PApplet. :-B

Normally, Processing can't find them when they're defined outside the sketch's level scope! :-SS

Anyways, Processing provides the undocumented PApplet::registerMethod() so we can have callbacks defined in our own classes findable by Processing.

However, I've got my doubts that would work under Python Mode. :-/

Therefore, you're better off simply using the regular sketch-scoped callbacks rather than having them inside other classes. :(

solub

ok, I feel like i'm struggling against some invisible force. But I'm not giving up yet.

So, following your suggestion I wrote the mouse event within the main .pyde file but once again (please forgive the beginner that I am) it's messy AND it doesn't work: def draw()

   #Draw particles
    for e in collection:
        e.display()

        def mousePressed():
            if e.over:
                e.target = True
            else:
                e.target = False

        def mouseDragged():
            if e.target:
                e.set(mouseX, mouseY)

The particle.py file looks now like this:

from toxi.physics2d import VerletParticle2D

class Particle(VerletParticle2D):

    def __init__(p, x, y):
        super(Particle, p).__init__(x, y)
        p.over = False
        p.target = False

    def display(p):
        if dist(p.x(), p.y(), mouseX, mouseY) < 4:
            p.over = True
            fill(255, 20, 20)
        else:
            p.over = False
            fill(255)

        ellipse(p.x(), p.y(), 4, 4)

solub

I tried many configurations (in the main sketch file, in a distinct function, in the draw(), in a child class...etc) but none worked. I have implemented mouse events before but it doesn't seem to work in this sketch specifically.

GoToLoop

You're creating functions inside a loop there! :-&
Callbacks need to go to the sketch-global-level scope. [-(

http://py.Processing.org/reference/mouseDragged.html
http://py.Processing.org/tutorials/interactivity/

solub

I know, I tried but it didn't work. That's why I started "experimenting" weird configurations. lol ~X(

solub

This won't work either so...

def setup():
    global over, target
    over = False
    target = False

   ...

def draw():
    global over, target

   ...

for e in collection:
    e.display()
    if dist(e.x(), e.y(), mouseX, mouseY) < 4:
        over = True
    else:
        over = False

   mousePressed()
   mouseDragged()
   mouseReleased()



def mousePressed():
    global over, target
    for e in collection:
        if over == True:
            target = True
        else:
            target = False

def mouseDragged():
    global target
    for e in collection:
        if target:
            e.set(mouseX, mouseY)

def mouseReleased():
    global target
    for e in collection:
        e.target = False

solub

This is the best I could figure out and it's still not working:

def setup():
    global over, target
    over = False
    target = False

   ...

def draw():
    global over, target

   ...

    for e in collection:
        e.display()
        if dist(e.x(), e.y(), mouseX, mouseY) < 4:
            over = True
        else:
            over = False

        if mousePressed and over == True:
            target = True
        else:
            target = False

        if target == True:
                mouseDragged()


    mouseReleased()


def mouseDragged():
    for e in collection:
        if mousePressed and over == True:
            e.set(mouseX, mouseY)

def mouseReleased():
    global target
    for e in collection:
        e.target = False

To get the dragging work I have to call the the mouseDragged() function. But it's still not working. Do you or anyone have any idea what's wrong ?

GoToLoop

I guess you should set apart your project here and learn how to drag objects 1st.
Found this random online Java Mode sketch below: :bz

https://OpenProcessing.org/sketch/472169

BtW, you're mixing up global variables w/ class instance variables. :-\"

solub

Working code below ! :

Particle class

from toxi.physics2d import VerletParticle2D

class particle(VerletParticle2D):

    def __init__(p, x, y):
        super(particle, p).__init__(x, y)
        p.over = False
        p.target = False


    def display(p):
        if dist(p.x(), p.y(), mouseX, mouseY) < 4:
            fill(255, 20, 20)
        else:
            fill(255)

        ellipse(p.x(), p.y(), 4, 4)


    def clicked(p, x, y):
        if dist(p.x(), p.y(), mouseX, mouseY) < 4:
            p.over = True
        else:
            p.over = False


    def stopDragging(p):
        p.over = False


    def drag(p, x, y):
        if p.over:
            p.set(x, y)

What's inside draw()

   ...

   #Draw particles
    for e in collection:
        e.display()
        e.drag(mouseX, mouseY)
   ...

Additional functions

def mousePressed():
    for e in collection:
        e.clicked(mouseX, mouseY)


def mouseReleased():
    for e in collection:
        e.stopDragging()

(Note the springs can be dragged but not the particles)

jeremydouglass

@solub -- thank you for sharing your solution!

Was draggable springs rather than particles what you wanted, in the end?

solub

@jeremydouglass Thank YOU and GoToLoop for the amazing help you're providing here. I'm sure it's possible to drag particles as well but I ended up only displaying springs so I'm fine with the code as it is.