Change a ui.NavigationView bar color

Phuket2

@robertiii , I took the method that @technoway wrote in post and just changed it to a function. So you should be able to call that function with an already presented uiView and a hex color. Look, I dont really have any exp using the ui.Navigation view. It’s a little funky. So the below may not work, but its a starting point. I think it will work.
Ok, hope it helps

import ui
from objc_util import ObjCInstance, UIColor
from time import sleep


def change_title_bar_color(v, hex_color):
    """ Change the title bar color to the passed color.
    """
    vv = ObjCInstance(v)
    bar_bckgnd = vv.superview().superview().superview().subviews()[1].subviews()[0]
    bar_bckgnd.backgroundColor = UIColor.colorWithHexString_(hex_color)


class MyClass(ui.View):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.make_view()

    def make_view(self):
        pass

if __name__ == '__main__':
    f = (0, 0, 300, 400)
    v = MyClass(frame=f)
    v.present(style='sheet', animated=False)
    '''
    You may or may not need the sleep method as I have done below. If I dont
    use it on my iPad pro, I get an error, something about obj does not have
    superview.  Basically going to fast. The function is being called before
    the view is fully created.
    if you didnt want the sleep, quite a few different ways you could work
    around it.
    Maybe one of the guys could comment if using @on_main_thread decorator on
    the function would stop this from happening or not.
    I could experiment, but I would not understand what is really happening.
    '''
    sleep(.01)
    change_title_bar_color(v, '#ff0000')

Phuket2

Sorry ignore all my comments about sleep. Just remove it. The problem comes from me using animated = False, when the view is presented.bJust dont use that param and it's fine.

robertiii

Thank you so much!!!!!!!

robertiii

So I tried it and got an error... Noneobject has type superview.

robertiii

I have figured out its because I placed it before the present. But if i place it after it doesn’t change

technoway

Hi. The method I wrote, that Phuket2 mentioned, was to change the title bar color, it probably won't work for your Navigation bar without modification.

I just put some code that JonB wrote into a method - he really did the heavy lifting.

JonB

If your navigationview is n:

ObjCInstance(n).navigationController().navigationBar().backgroundColor=UIColor.redColor()

etc

robertiii

For some reason this fails to change the color, but no errors are given.

JonB

@JonB said:

ObjCInstance(n).navigationController().navigationBar().backgroundColor=UIColor.redColor()

sorry, i meant

ObjCInstance(nav).navigationController().navigationBar()._backgroundView().backgroundColor=UIColor.redColor()

robertiii

Still nothing changes. I’m not sure what I’m doing.

JonB

import ui
from objc_util import *
v=ui.View(frame=(0,0,576,576),bg_color='blue',name='view')
nav = ui.NavigationView(v,name='nav view')
v.left_button_items = [ui.ButtonItem(image=ui.Image.named('ios7_film_256'))]
ObjCInstance(nav).navigationController().navigationBar()._backgroundView().backgroundColor=UIColor.redColor()
nav.present('landscape')

does this give you a white "nav view" bar on top, with a red "view" bar, followed by a blue main view?
if not, try

import ui
from objc_util import *
v=ui.View(frame=(0,0,576,576),bg_color='blue',name='view')
nav = ui.NavigationView(v,name='nav view')
v.left_button_items = [ui.ButtonItem(image=ui.Image.named('ios7_film_256'))]
def changecolor():
      ObjCInstance(nav).navigationController().navigationBar()._backgroundView().backgroundColor=UIColor.redColor()
nav.present('landscape') 
ui.delay(changecolor, 2)

robertiii

The second works. So apparently there is no way to change it before presenting?

Phuket2

@robertiii, to me appears you have to present it first. I just did some tests, and it appears to me it's impossible just using Pythonista ui methods to create an invisible view. Not sure why @omz choose not to have a param in the present method to allow the view to be hidden on presentation. Could be some technical issue. I did try setting the views hidden attr to True be presenting. It does not work. But interestingly, if you set the view's bg_color to say 'blue' and have the views hidden attr set to True, you dont see the bg_color when the views presented.
I also tried the same with a second view after the first view had be created and presented on the screen. Same results. I tried this just in case it made a difference if there was at least one view presented on the screen or not. Maybe someone has more insight to this,

JonB

you might try wrapping changecolor with a @on_main_thread. I am pretty sure i was able to change color prior to present, but maybe present is changing some defaults.

@phuket
present does not automatically set hidden=False (panel does, sheet does not). not being presented (no parent) and being hidden are two completely separate things.