Kivy how to rotate a picture

Question

i'm trying to rotate some pictures i have to show on the screen, these picture are inside a stacklayout, and i need to show them as Portrait instead of landscape,i'm using the Image Widget Thanks

Answer 1

The previous 2 answer of toto_tico is a way to do, but i would rather create a new widget for it, and use it:

Builder.load_string('''
<RotatedImage>:
    canvas.before:
        PushMatrix
        Rotate:
            angle: root.angle
            axis: 0, 0, 1
            origin: root.center
    canvas.after:
        PopMatrix
''')

class RotatedImage(Image):
    angle = NumericProperty()

Then, use this widget as other Image widget, you just have a "angle" property you can play with.

Note: the collision detection is not handled on the image, except in the scatter example. Scatter can be expensive just for rotate something, but at least the collision works.

Answer 2

I don't think the Scatter is meant to be use for this. But I guess is a more intuitive solution. The Scatter includes a rotation (and also a scale) property.

Basically, I embedded the Image inside a Scatter and use the rotation property to rotate 90 degrees.

Why do I say the Scatter is not meant for this task. Basically because it allows gestures over it. You can basically translate, rotate or scale with your fingers (or using the multi-touch mouse emulation). That is why in the next example I am setting the do_scale, do_rotation and do_translation to false. I am clarifying this before you get confuse with the do_rotation: false

from kivy.app import App
from kivy.uix.stacklayout import StackLayout
from kivy.lang import Builder

Builder.load_string("""
<Example>:
    Image:
        source: 'kivy.png'
        size_hint: None,None
        size: 64,64
    Scatter:
        pos: 0,0
        size_hint: None,None
        size: 64,64
        do_rotation: False
        do_scale: False
        do_translation: False
        rotation: 90
        Image:
            source: 'kivy.png'
            size_hint: None,None
            size: 64,64

""")

class Example(App, StackLayout):
    def build(self):
        return self

if __name__ == "__main__":
    Example().run()