From python to qml

Pablo J. Rogina

@Akhou so for me the issue is just about Python templating, not related to Qt or QML itself.

Not that I'm very proficient with Python, but it looks like you can use simple string.Template or more sophisticated template engines (i.e Genshi).

I'd essentially create a template for the QML layout you want having the proper placeholders for the coordinates, and then the same Python script doing shape detection and calculating coordinates will process the template and provide the actual values, without the need to create any text file.

So in just one pass you'll end up with a QML file with everything set.

Akhou

It seems to be the perfect solution for my problem, but I'm not familiar with Genshi, and unfortunatly the tuto that they provided is far from what I intend to do!
I don't know what to do :/ !

Pablo J. Rogina

@Akhou said in From python to qml:

I don't know what to do :/ !

So you won't do anything? :-(

If a template engine is too much, why don't you try with string.Template? have you look at the example I suggested? Have you look for more examples?

Akhou

@Pablo-J.-Rogina said in From python to qml:

string.Template

I have to do something, but genshi seems to be hard and there isn't alot of examples online, so I'll see what can I do with string.template

Thank u

Akhou

But is string.Template able to generate a .qml file??

SGaist

A qml file is just a text file. So you can write your "string rendered template" in it and be done with it.

Akhou

so for this example

import string 
v={'var1':'screen'}
x=string.Template("""
{
id      :$var1
width   :22
height  :123
            """)
print'Item: ', x.substitute(v)
y="""
{
 id      :$sm1
 x       :11
 y       :8
 width   :12
 height  :65

  }
}  
 """
print 'Rectangle ' , y%v

I wanted to add to it "string rendered template" but I couldn't figure where to place it exactly, I tried to work with this example :

from flask import Flask, render_template
from flask import request, jsonify

app = Flask(__name__)

@app.route('/', methods=['GET', 'POST'])
def homepage():
    if request.method == 'POST':
        f1 = request.form['firstVerb'] 
        f2 = request.form['secondVerb']
    return render_template('index.html', f1=f1, f2=f2)
    
if __name__ == "__main__":
   app.run(debug=True)

but I keep getting this message :

Restarting with stat

Could u pls show me how to integrated rendered template to my example!
Thank u ^^

SGaist

Are you trying to render QML through a web browser ?

SGaist

Flask already uses jinja for templating as shown in their tutorial.

Akhou

no, I need to generate a .qml file from my template( that I mentioned in the previous text), but it's just an example that I found online, I wanted to try it, but I kept having this message : Restarting with stat
So I'm kinda out of ideas!

Akhou

This is what I came with till now:

  if shape == "rectangle":
            x,y,w,h = cv2.boundingRect(c)
            cv2.rectangle(image,(x,y),(x+w,y+h),(0,255,0),0)
            from string import Template
            from string import Template
            def main():
                cordinates=[]
                cordinates.append(dict(abscisse=x,ordonee=y,width=w,height=h))
                t=Template("""
            x: $abscisse
            y: $ordonee
           w: $width
           h: $height
                       """)                
                print '    Rectangle:'
                print("      {")
                for data in cordinates:
                    print (t.substitute(data))
                    print("      }")
            if __name__=="__main__":                
                main()

and from this template I need to generate a .qml file!
any ideas!!

Pablo J. Rogina

@Akhou the idea is to have a text file as template using QML syntax and some placeholders, and then process that file filling such variables with the results of your calculations. This is a basic example that will create a main.qml file:

template.py

import string

if __name__ == '__main__':

    # Open template file and pass string to 'data'.
    # Will be in QML syntax except with the string.Template replace tags
    # with the format of '$var'. The 'var' MUST correspond to the items
    # that will be calculated (i.e. coordinates, sizes, ids, etc.)
    with open('qml_template.txt', 'r') as my_template:
        data = my_template.read()
        # Print template for visual cue.
        print('Template loaded:')
        print(data)
        # Pass 'data' to string.Template object data_template.
        data_template = string.Template(data)

    # Do the process for shape detection and coordinate calculation
    # ...

    # For the sake of simplicity, here values are stored in a dictionary
    values = dict(x=10, y=20, w=200, h=100)

    # Open QML output file and fill its contents by string substitution
    with open("main.qml", 'w') as output_file:
        # Run string.Template substitution on data_template
        # using data from 'values' as source and write to 'output_file'.
        output_file.write(data_template.substitute(values))
        output_file.close()

    # Print QML generated code for visual cue.
    with open('main.qml', 'r') as my_qml:
        qml_code = my_qml.read()
        print('QML code generated:')
        print(qml_code)

qml_template.txt

import QtQuick 2.2

Item {
    id: it
    width: 600
    height: 480

    Rectangle {
        id: rect
        x: $x
        y: $y
        width: $w
        height: $h
    }
}

and the rest is magic...

Akhou

I can't thank u enough for ur help
Thank u so much

Pablo J. Rogina

@Akhou well, at least you could:

Upvote the answer(s) that helped you to solve the issue
Use the "Topic Tools" button to mark your post as Solved

:-)