How to allow user to choose file as background image in kivy? - python

Or, how to do so using python, give it an ID, and set it as background image in kv language?
I would like to be able to draw on top of an image instead of a black screen, which I am doing here:
edited
new problem: upload button does not work, here is new code
from random import random
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.graphics import Color, Line, Rectangle
from kivy.uix.filechooser import FileChooserListView, FileChooserIconView
from kivy.uix.floatlayout import FloatLayout
class MyPaintWidget(Widget):
def on_touch_down(self, touch):
color = (random(), random(), random())
with self.canvas:
Color(*color)
d = 30.
touch.ud['line'] = Line(points=(touch.x, touch.y))
def on_touch_move(self, touch):
touch.ud['line'].points += [touch.x, touch.y]
class MyPaintApp(App):
def build(self):
parent = Widget()
painter = MyPaintWidget()
Choose = Button(text = 'upload image')
parent.add_widget(painter)
parent.add_widget(Choose)
def chooose_file(obj):
fc = FileChooserIconView(title= 'upload image')
image_path = self.fc.selection[0]
image_name = file_path.split('/')[-1]
with self.canvas.before:
Rectangle(
size=self.size,
pos=self.pos,
source=image_name)
Choose.bind(on_release=choose_file)
return parent
if __name__ == '__main__':
MyPaintApp().run()

What about this:
If you used the kivy filechooser to get the user to select an image file,
then you could use the .selection attribute of the filechooser to get the name and/or path of that file. Once you have that, you could use it to set the source of a Rectangle on the canvas of the layout etc. where you want the background image.
For instance, to set a background image on a BoxLayout, inside the class that inherits from the BoxLayout:
fc = FileChooserIconView(title="Choose Image")
image_path = self.fc.selection[0]
image_name = file_path.split('/')[-1]
with self.canvas.before:
Rectangle(
size=self.size,
pos=self.pos,
source=image_name)
This is of course a very simplistic example, and isn't really taking the rest of your code into account, but with the kivy docs on FileChooser you should get it. Worth noting also that you could do this in the kv file, perhaps much more cleanly.

Related

Python Kivy - Save canvas to a file

Here I have a simple kivy paint app taken from their docs https://kivy.org/doc/stable/tutorials/firstwidget.html and modified by me, attempting to add a save button which would save the canvas to the file image.jpg
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.graphics import Color, Ellipse, Line
class MyPaintWidget(Widget):
def on_touch_down(self, touch):
with self.canvas:
Color(255, 255, 255)
Ellipse(pos=(touch.x/ 2, touch.y/ 2), size=(1, 1))
touch.ud['line'] = Line(points=(touch.x, touch.y))
def on_touch_move(self, touch):
touch.ud['line'].points += [touch.x, touch.y]
class MyPaintApp(App):
def build(self):
parent = Widget()
self.painter = MyPaintWidget()
clearbtn = Button(text='Clear',font_size=30,pos=(100,0))
clearbtn.bind(on_release=self.clear)
savebtn = Button(text='Save',font_size=30)
savebtn.bind(on_release=self.save)
parent.add_widget(self.painter)
parent.add_widget(savebtn)
parent.add_widget(clearbtn)
return parent
def save(self, obj):
self.painter.export_as_image().save('image.jpg')
def clear(self, obj):
self.painter.canvas.clear()
MyPaintApp().run()
the save button does appear next to the clear button, and it does create the file image.jpg when I click it. But for some reason the file is always a blank black image with nothing on it, instead of the canvas with whatever I have drawn.
The problem is that your MyPainter widget has its default size of (100,100), and its default position of (0,0), so it is actually behind your Save Button. Any drawing that you do in the middle of the App display is not in the MyPainter widget, so saving to an image will be blank.
The fix is to set pos and size of the MyPainter widget so that it can be drawn on. You probably also want to use collide_point() in your on_touch_down() and on_touch_move() methods to ensure that you can only draw in the MyPainter widget.

Dynamic grid in Kivy with each grid element containing multiple widgets

This is my first post here, but I will try to be as detailled as I can.
So my application is in python, and involves a grid in kivy, where each element in the grid is supposed to contain 4 additional widgets and possibility for a fifth. The four additional widgets are supposed to be in a cross shape at the edges and the fifth in the middle.
Problem is, whenever I add a sub widget it lands in the bottom left corner on position 0,0 of the main window
So far so good. Right now I am just trying to get even one widget inside another widget to display correctly.
Heres what I attempted:
<GridCell#Label>
BoxLayout:
orientation:'horizontal'
Button:
text:'One'
size:10,10
size_hint:None,None
Building a .kv file for my app, where I would put a box layout inside of it and then a button.
Also I tried the following class configuration:
class GridCell(Label):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.root = FloatLayout()
self.button = Button(text="test")
self.button.x = self.root.x
self.button.center_y = self.root.center_y
self.root.add_widget(self.button)
self.add_widget(self.root)
Also did not work.
I am adding the grid cells by just calling .add on the grid with a newly created widget for each iteration of a for loop.
All the child widgets are apparently created, but they all land in the bottom left corner!
This is the whole code of the gui right now:
import kivy
import World
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.gridlayout import GridLayout
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics import Color, Rectangle
kivy.require('1.10.0')
class GridCell(Label):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.root = FloatLayout()
self.button = Button(text="blargh")
self.button.x = self.root.x
self.button.center_y = self.root.center_y
self.root.add_widget(self.button)
self.add_widget(self.root)
def on_size(self, *args):
self.canvas.before.clear()
if self.id is "cliff":
with self.canvas.before:
Color(249 / 255, 6 / 255, 6 / 255, 0.3)
Rectangle(pos=self.pos, size=self.size)
if self.id is "goal":
with self.canvas.before:
Color(6 / 255, 6 / 255, 249 / 255, 0.3)
Rectangle(pos=self.pos, size=self.size)
if self.id is "start":
with self.canvas.before:
Color(11 / 255, 174 / 255, 6 / 255, 0.3)
Rectangle(pos=self.pos, size=self.size)
if self.id is "normal":
with self.canvas.before:
Color(119 / 255, 115 / 255, 115 / 255, 0.3)
Rectangle(pos=self.pos, size=self.size)
class GameGridApp(App):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.grid = GridLayout(cols=8, rows=5)
self.load_into()
def load_into(self):
world = World.World(8, 5)
world.build_gamegrid()
for cell in world.gamegrid:
name = str(cell.name)
grid_cell = GridCell()
grid_cell.text = name
if cell.start:
grid_cell.id = "start"
if cell.goal:
grid_cell.id = "goal"
if cell.cliff:
grid_cell.id = "cliff"
if cell.field:
grid_cell.id = "normal"
self.grid.add_widget(grid_cell)
def build(self):
return self.grid
customLabel = GameGridApp()
customLabel.run()
I may give an idea , that create a 'subgrids' object and a 'main grid' object that contain the 'subgrids'. These two objects would be GridLayout objects.
Here is a simple example in python2.7 :
import kivy
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
class SubGrids(GridLayout):
def __init__(self):
GridLayout.__init__(self, cols=3, rows=3);
self.add_widget(Label(text='1st'));
self.add_widget(Label(text=''));
self.add_widget(Label(text='2nd'));
self.add_widget(Label(text=''));
self.add_widget(Label(text='3rd'));
self.add_widget(Label(text=''));
self.add_widget(Label(text='4th'));
self.add_widget(Label(text=''));
self.add_widget(Label(text='5th'));
class Grids(GridLayout):
def __init__(self):
GridLayout.__init__(self, cols=2, rows = 2);
self.add_widget(SubGrids());
self.add_widget(SubGrids());
self.add_widget(SubGrids());
self.add_widget(SubGrids());
class Example(App):
def build(self):
return Grids()
if __name__ == '__main__':
x = Example();
x.run();
Hope this gives an idea.

Python / Kivy - Changing Screen with phone screen orientation (android)

I haven't found anything on the internet so far, all I want to know is if its possible to change the current screen in kivy depending on the orientation of the phone's screen (Landscape or portrait) and how to do it. or at least a link to a tutorial because I couldn't find one myself.
I haven't found a way of doing this by recognizing the android device's orientation. However, the following program changes it's contents by comparing the window's height and width. The program's Label changes dynamically, so when the width is greater (landscape mode) it's Label has a different text then when the height is greater (portrait mode). Currently it works on Windows, but unfortunately I don't have a Linux system to build an android version. Theoretically it should work, but i'm not 100% sure.
from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.label import Label
from kivy.graphics import Rectangle, Color
class MainScreen(FloatLayout, Label):
"""MAIN WINDOW CLASS"""
def __init__(self, **kwargs):
super(MainScreen, self).__init__(**kwargs)
with self.canvas.before:
Color(0.988, 0.725, 0.074, 1, mode='rgba')
self.rect = Rectangle(pos=self.pos, size=self.size)
self.bind(size=self.update_rect)
self.titlos = Label(text="",
bold=True,
text_size=(None,None),
font_size="20sp",
pos_hint={'center_x': 0.5, 'center_y': .85},
size_hint_y=None,
size = self.size,
height=self.texture_size[1],
halign="center",
valign = "middle",
color=(0.055, 0.235, 0.541, 1))
self.add_widget(self.titlos)
self.bind(size=self.update_orientation)
def update_rect(self, *args):
"""FUNCTION TO UPDATE THE RECATANGLE OF CANVAS TO FIT THE WHOLE SCREEN OF MAINSCREEN ALWAYS"""
self.rect.pos = self.pos
self.rect.size = self.size
def update_orientation(self, *args):
"""FUNCTION TO UPDATE THE SCREEN CONTENTS WHEN THE WINDOW SIZE CHANGES"""
if self.parent.size[1] > self.parent.size[0]:
self.titlos.text = "This is\nPortrait\nOrientation"
else:
self.titlos.text = "This is Landscape Orientation"
# This is just for checking. Not essential to the program.
print("Width:", self.parent.size[0], ", Height:", self.parent.size[1])
class main(App):
"""BUILDING THE APP"""
def build(self):
return MainScreen()
if __name__ == "__main__":
main().run()
You can use the update_orientation function to include whatever you need to change when the orientation changes.

Autoresizing Canvas in a Kivy App

I am writing my first Kivy app in python only (I'm avoiding kv for now). I have created a custom widget called WorldviewWidget, and I'm trying to use it as a place to draw. With the button widgets, I just give a size_hint and a pos_hint, and they show up where I want them. But with my widget, I don't know how to use the size_hint and position_hint to size the rectangle I am drawing in my WorldviewWidget. Here is the code. Thanks in advance!
#! /usr/bin/python
from kivy.app import App
from kivy.graphics import *
from kivy.core.window import Window
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.widget import Widget
from kivy.uix.button import Button
class WorldviewWidget(Widget):
def __init__(self, **kwargs):
super(WorldviewWidget, self).__init__(**kwargs)
self.canvas.clear()
print self.size, self.pos
with self.canvas:
Color(1, 0, 0, 1, mode='rgba')
# HELP! I want the rectangle to be resized when the window changes size so that it always takes up the same proportion of the screen.
self.rect = Rectangle(size=???, pos=???)
class JFROCS_App(App):
def build(self):
Window.clearcolor = [1,1,1,1]
parent = FloatLayout(size=Window.size)
worldview = WorldviewWidget(size_hint=(0.4, 0.4), pos_hint = {'x':0.2, 'y':0.2})
parent.add_widget(worldview)
start_btn = Button(text='Start', size_hint=(0.1, 0.1), pos_hint={'x':.02, 'y':.7}, background_color=[0,1,0,1])
start_btn.bind(on_release=self.start_simulation)
parent.add_widget(start_btn)
pause_btn = Button(text='Pause', size_hint=(0.1,0.1), pos_hint={'x':.02, 'y':.6}, background_color=[1,1,0,1])
pause_btn.bind(on_release=self.pause_simulation)
parent.add_widget(pause_btn)
stop_btn = Button(text='Stop', size_hint=(0.1,0.1), pos_hint={'x':.02, 'y':.5}, background_color=[1,0,0,1])
stop_btn.bind(on_release=self.stop_simulation)
parent.add_widget(stop_btn)
return parent
def start_simulation(self, obj):
print "You pushed the start button!"
def pause_simulation(self, obj):
print "You pushed the pause button!"
def stop_simulation(self, obj):
print "You pushed the stop button!"
if __name__ == '__main__':
JFROCS_App().run()
I think that this sort of task is predestined for the kivy-language but here is a solution in Python. Basically, I have used the bind-method to make your widget listen for changes in its parent's size. Have a look at this for more information on this mechanism.
from kivy.app import App
from kivy.graphics import *
from kivy.core.window import Window
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.widget import Widget
from kivy.uix.button import Button
class WorldviewWidget(Widget):
def __init__(self, **kwargs):
super(WorldviewWidget, self).__init__(**kwargs)
self.canvas.clear()
print self.size, self.pos
with self.canvas:
Color(1, 0, 0, 1, mode='rgba')
# *changed* ##############################################
self.rect = Rectangle(size=self.size, pos=self.pos)
# *new* ##########################################################
def update_size(self, instance, new_size):
print "UPDATING SIZE", instance, new_size
self.size[0] = new_size[0] * 0.4
self.size[1] = new_size[1] * 0.4
self.rect.size = self.size
self.pos[0] = self.parent.size[0] * 0.2
self.pos[1] = self.parent.size[1] * 0.2
self.rect.pos = self.pos
class JFROCS_App(App):
def build(self):
Window.clearcolor = [1,1,1,1]
parent = FloatLayout(size=Window.size)
# *changed* ##################################################
worldview = WorldviewWidget(size=(0.4*parent.size[0], 0.4*parent.size[1]),
pos=(0.2*parent.size[0], 0.2*parent.size[1]))
# makes sure that the widget gets updated when parent's size changes:
parent.bind(size=worldview.update_size)
parent.add_widget(worldview)
start_btn = Button(text='Start', size_hint=(0.1, 0.1), pos_hint={'x':.02, 'y':.7}, background_color=[0,1,0,1])
start_btn.bind(on_release=self.start_simulation)
parent.add_widget(start_btn)
pause_btn = Button(text='Pause', size_hint=(0.1,0.1), pos_hint={'x':.02, 'y':.6}, background_color=[1,1,0,1])
pause_btn.bind(on_release=self.pause_simulation)
parent.add_widget(pause_btn)
stop_btn = Button(text='Stop', size_hint=(0.1,0.1), pos_hint={'x':.02, 'y':.5}, background_color=[1,0,0,1])
stop_btn.bind(on_release=self.stop_simulation)
parent.add_widget(stop_btn)
return parent
def start_simulation(self, obj):
print "You pushed the start button!"
def pause_simulation(self, obj):
print "You pushed the pause button!"
def stop_simulation(self, obj):
print "You pushed the stop button!"
if __name__ == '__main__':
JFROCS_App().run()
And have a look at the kivy-language -- it takes care of all the binding for you :)

Kivy accordion interaction

I have images loading in the kivy accordion and I want to print out the x and y coordinates below the images when I press the mouse button. I can't for the life of my figure this out. Every time I add anything it seems like it shuts the whole program down. I know that the widget I have will print to the console but I want to print it to the screen.
Here is the code I am using:
from kivy.uix.accordion import Accordion, AccordionItem
from kivy.uix.image import Image
from kivy.app import App
from kivy.uix.widget import Widget
class MouseWidget(Widget):
def on_touch_down(self, touch):
print(touch)
class MyApp(App):
def build(self):
root = Accordion(orientation='horizontal')
item= AccordionItem(title='Picture1')
src = "picture1.png"
image = Image(source=src,pos=(200, 100))
# add image to AccordionItem
item.add_widget(image)
root.add_widget(item)
item= AccordionItem(title='Picture2')
src = "picture2.png"
image = Image(source=src,pos=(200, 100))
# add image to AccordionItem
item.add_widget(image)
root.add_widget(item)
return root
if __name__ == '__main__':
MyApp().run()
Here's a simple modification to your program that adds the touch position to a label below the image, using kivy language to automatically bind to the necessary properties so that the display is updated when they change.
I'm not sure what problems you had in particular, so let me know if the way it works is not clear!
from kivy.uix.accordion import Accordion, AccordionItem
from kivy.uix.image import Image
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivy.properties import ObjectProperty, StringProperty
from kivy.uix.boxlayout import BoxLayout
Builder.load_string('''
<MouseWidget>:
image: image
label: label
orientation: 'vertical'
Image:
id: image
source: root.source
Label:
id: label
size_hint_y: None
height: 50
text: 'no touch detected'
''')
class MouseWidget(BoxLayout):
image = ObjectProperty()
label = ObjectProperty()
source = StringProperty()
def on_touch_down(self, touch):
if self.image.collide_point(*touch.pos):
self.label.text = str(touch.pos)
def on_touch_up(self, touch):
self.label.text = 'no touch detected'
class MyApp(App):
def build(self):
root = Accordion(orientation='horizontal')
item= AccordionItem(title='Picture1')
src = "picture1.png"
image = MouseWidget(source=src)
# add image to AccordionItem
item.add_widget(image)
root.add_widget(item)
item= AccordionItem(title='Picture2')
src = "picture2.png"
image = MouseWidget(source=src)
# add image to AccordionItem
item.add_widget(image)
root.add_widget(item)
return root
if __name__ == '__main__':
MyApp().run()
Every time I add anything it seems like it shuts the whole program down.
This sounds like your changes crashed the program. You should check the output of your program by running it in a terminal. It will print information about the error that can help you track down your mistakes.

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