Inconsistent color parsing, invalid RGBA values

[zrzka]

System Information

• Pythonista 3.2 (320000), Default interpreter 3.6.1
• iOS 11.2.2, model iPad7,2, resolution (portrait) 2048.0 x 2732.0 @ 2.0

Working device

User has no issue on iOS 9.3.5, iPad Mini, Pythonista 3.2.

Issues

• Designer produces invalid RGBA values (negative)
• Inconsistent color parsing and presentation

Related issues

Probably relates to https://github.com/omz/Pythonista-Issues/issues/374 where you did mention that color parsing is kind of incosistent in the Pythonista.

Also maybe there's difference in how UIColor handles negative values when you do call colorWithRed:green:blue:alpha between iOS 9 and iOS11? Guessing.

Description

See this thread. 7points user somehow managed to create tint_color in .pyui file with following values:

• RGBA(1.000000,-0.021739,-0.021739,1.000000)

Green is negative, blue is negative.

Inspector in the UI designer shows this color as fffffffb

I would expect ff0000ff.

Alert view shows this color as fffffffa

I would expect ff0000ff, or at least ff0000 (see 3).

Alert view doesn't accept color with alpha channel

Only six 0-9a-f's can be used. Seventh and eight (alpha channel) are ignored.

I would expect that alpha channel is accepted as well.

Designer shows correct color

Looks like that designer really parses it as ff0000ff.

Running script

But when you run it, it shows default color.

Sample files

tint.py:

import ui

v = ui.load_view()
v.present('sheet')

tint.pyui:

[
  {
    "nodes" : [
      {
        "nodes" : [

        ],
        "frame" : "{{60, 106}, {120, 29}}",
        "class" : "SegmentedControl",
        "attributes" : {
          "flex" : "LR",
          "segments" : "Hello|World",
          "frame" : "{{60, 106}, {120, 29}}",
          "tint_color" : "RGBA(1.000000,-0.021739,-0.021739,1.000000)",
          "uuid" : "B7DD73C0-65AF-42DE-B501-6403EC9466B7",
          "class" : "SegmentedControl",
          "name" : "segmentedcontrol1"
        },
        "selected" : false
      }
    ],
    "frame" : "{{0, 0}, {240, 240}}",
    "class" : "View",
    "attributes" : {
      "enabled" : true,
      "background_color" : "RGBA(1.000000,1.000000,1.000000,1.000000)",
      "tint_color" : "RGBA(0.000000,0.478000,1.000000,1.000000)",
      "border_color" : "RGBA(0.000000,0.000000,0.000000,1.000000)",
      "flex" : ""
    },
    "selected" : false
  }
]

[zrzka]

Glad we have all these simulators ...

UIColor *color = [UIColor colorWithRed:1.000000 green:-0.021739 blue:-0.021739 alpha:1.000000];

CGFloat red = 0.0, green = 0.0, blue = 0.0, alpha = 0.0;
[color getRed:&red green:&green blue:&blue alpha:&alpha];

NSLog(@"R %f G %f B %f A %f", red, green, blue, alpha);
NSLog(@"%@", color);

iOS 9.3

R 1.000000 G 0.000000 B 0.000000 A 1.000000
UIDeviceRGBColorSpace 1 0 0 1

iOS 11.2

R 1.000000 G -0.021739 B -0.021739 A 1.000000
UIExtendedSRGBColorSpace 1 -0.021739 -0.021739 1

It seems that iOS 9.3 clamps color components values. And maybe it's not related at all.

[zrzka]

Despite the fact that the different iOS versions handles this color differently, when I try to tint button with this particular color in simulator / device, it works. So the problem is elsewhere.

[zrzka]

7points user forum follow up

I think I have found the reason for the bug: the color picker of the ui-Designer. When sliding over the colors, the hex value sometimes jumps from 6 digits to eight digits. Since 8-digit values ​​are wrong for ipad pro edition 2015, they will be ignored.