feat: implement `CircularScale` widget by amansxcalibur · Pull Request #156 · Fabric-Development/fabric

amansxcalibur · 2026-01-09T19:33:40Z

This PR introduces a new widget, CircularScale which aims to behave as a circular analogue to Scale.

Features

The Circular Scale has three gadgets (all the same level in hierarchy, unlike Scale):

CircularScale
├── trough
├── highlight
└── slider

Gadget	Property	Effect
slider	`min-width`	Slider thickness
	`min-height`	Slider height
	`margin-left`	Angular gap before the slider and before the start of the progress arc
	`margin-right`	Angular gap after the slider and after the end of the trough arc
	`border-radius`	Rounded corners
highlight	`background-color`	Color of the progress arc
highlight	`min-width/height/border-width`	Thickness of the progress arc
trough	`background-color`	Color of the trough arc
trough	`min-width/height/border-width`	Thickness of the trough arc
Base styles
`background-color`		Background color of the widget (circular)

Performance

The CircularScale is approximately 5.8x faster in draw cycles compared to CircularProgressBar. Its probably because of the gadgets usage.

Suggestions

Add independant margin support to the progress and trought arc
As of now, the arcs reflect the margins of the slider, which works fine, but adding it would make the widget more configurable.
More styling (borders, gradients, background-image, etc).

cir-scale-demo-2.mp4

amansxcalibur · 2026-01-09T19:34:43Z

Examples are also up. Override do_draw_trough_arc, do_draw_progress_arc and do_draw_slider for custom logic.

its-darsh

Look pal, I love you and all, but you know the rules. If you wanna get this merged, you gotta hurt your fingers and add LOTs of typing defs.

its-darsh · 2026-01-10T14:13:18Z

+        self.slider_ctx = self.do_create_gadget_context("slider")
+        self.highlight_ctx = self.do_create_gadget_context("highlight")
+
+    def do_get_thickness_from_context(self, context, state):


The naming of this function is just too broad, use do_get_border_width, and please add function typing for the signature (each parameter and return type.)

its-darsh · 2026-01-10T14:13:51Z

+        self.trough_ctx = self.do_create_gadget_context("trough")
+        self.slider_ctx = self.do_create_gadget_context("slider")
+        self.highlight_ctx = self.do_create_gadget_context("highlight")


Use _ prefixes for private variables.

its-darsh · 2026-01-10T14:14:48Z

+
+
+class CircularScale(CircularProgressBar):
+    NON_ROUND_CAP_DELTA = 0.01


Use a class input parameter with a default value instead.

its-darsh · 2026-01-10T14:15:12Z

+    def __init__(self, **kwargs):
+        super().__init__(**kwargs)


You need to provide a full signature for the class, we do not take typing easily.

its-darsh · 2026-01-10T14:15:52Z

+    def do_calculate_safe_radius(
+        self, delta, slider_height, progress_thickness, trough_thickness
+    ):
+        max_thickness = max(slider_height, progress_thickness, trough_thickness)


Useless variable, inline it instead.

its-darsh · 2026-01-10T14:25:16Z

+        else:
+            rtl, rtr, rbr, rbl = map(float, radius)
+
+        rtl, rtr, rbr, rbl = [max(0.0, v) for v in [rtl, rtr, rbr, rbl]]


Use a tuple notation instead of a list, saves on memory.

its-darsh · 2026-01-10T14:25:48Z

+        cr.restore()
+        return False
+
+    def do_create_gadget_context(self, node_name):


Function signature missing.

its-darsh · 2026-01-10T14:26:01Z

+        ctx.set_path(path)
+        return ctx
+
+    def do_draw_rounded_rect(self, cr, x, y, width, height, radius):


Function signature missing.

its-darsh · 2026-01-10T14:27:21Z

+        factor = 1.0
+
+        # top edge
+        if (rtl + rtr) > width:
+            factor = min(factor, width / (rtl + rtr))
+        # bottom edge
+        if (rbl + rbr) > width:
+            factor = min(factor, width / (rbl + rbr))
+        # left edge
+        if (rtl + rbl) > height:
+            factor = min(factor, height / (rtl + rbl))
+        # right edge
+        if (rtr + rbr) > height:
+            factor = min(factor, height / (rtr + rbr))
+
+        if factor < 1.0:
+            rtl *= factor
+            rtr *= factor
+            rbr *= factor
+            rbl *= factor


Merge into a single inline expression using inline ifs.

its-darsh · 2026-01-10T14:27:57Z

+        if rtl > 0:
+            cr.arc(x + rtl, y + rtl, rtl, math.pi, 3 * math.pi / 2)
+
+        cr.close_path()


Consider moving do_draw() below all class' methods.

amansxcalibur · 2026-01-10T23:51:33Z

The widget needs css class type support for gadgets. Will update soon.

its-darsh · 2026-01-11T08:24:47Z

Should it be a draft instead?

amansxcalibur · 2026-01-11T09:03:38Z

Yes, I'll let u know once it's ready for review

its-darsh · 2026-01-11T15:36:39Z

+        super().__init__(
+            value=value,
+            min_value=min_value,
+            max_value=max_value,
+            start_angle=start_angle,
+            end_angle=end_angle,
+            line_width=line_width,
+            line_style=line_style,
+            pie=pie,
+            invert=invert,
+            child=child,
+            name=name,
+            visible=visible,
+            all_visible=all_visible,
+            style=style,
+            style_classes=style_classes,
+            tooltip_text=tooltip_text,
+            tooltip_markup=tooltip_markup,
+            h_align=h_align,
+            v_align=v_align,
+            h_expand=h_expand,
+            v_expand=v_expand,
+            size=size,
+            **kwargs,
+        )


use CircularProgressBar.__init__(self, <STUFF>) and do not use keyword arguments.

its-darsh · 2026-01-11T15:38:16Z

+        self.do_draw_progress_arc(
+            cr=cr,
+            center_x=center_x,
+            center_y=center_y,
+            safe_radius=safe_radius,
+            start_angle=start_angle,
+            progress_angle=progress_angle,
+            progress_color=progress_color,
+            progress_thickness=progress_thickness,
+            progress_line_width_angle=progress_line_width_angle,
+            slider_thickness_angle=slider_thickness_angle,
+            left_gap_angle=left_gap_angle,
+        )
+
+        self.do_draw_slider(
+            cr=cr,
+            center_x=center_x,
+            center_y=center_y,
+            safe_radius=safe_radius,
+            progress_angle=progress_angle,
+            slider_color=slider_color,
+            slider_thickness_angle=slider_thickness_angle,
+            slider_height=slider_height,
+            corner_radius=corner_radius,
+        )
+
+        self.do_draw_trough_arc(
+            cr=cr,
+            center_x=center_x,
+            center_y=center_y,
+            safe_radius=safe_radius,
+            progress_angle=progress_angle,
+            real_end_angle=real_end_angle,
+            trough_color=trough_color,
+            trough_thickness=trough_thickness,
+            trough_line_width_angle=trough_line_width_angle,
+            slider_thickness_angle=slider_thickness_angle,
+            right_gap_angle=right_gap_angle,
+        )


its-darsh · 2026-01-19T23:17:35Z

Are we ready, son?

amansxcalibur · 2026-01-19T23:51:22Z

@its-darsh I told you about the implementation issues right. I haven't really checked on it since then.

…ding its `WidgetPath`

…raw cycles

its-darsh · 2026-04-11T10:36:12Z

Once you finish this hit me up with a mention, also don't forget to run ruff with ruff.toml as your config.

amansxcalibur · 2026-04-12T14:43:10Z

@its-darsh Alright, its done. Gtk style engine optimization needs to be studied smh

its-darsh · 2026-04-14T04:02:36Z

Should I merge then?

If so I need you to do a sanity ruff lint.

amansxcalibur · 2026-04-14T04:12:02Z

All checks passed when put against ruff.toml

its-darsh · 2026-04-17T16:10:57Z

Every person gets one.

amansxcalibur force-pushed the main branch from 94b8864 to 6c00efd Compare January 9, 2026 19:37

its-darsh requested changes Jan 10, 2026

View reviewed changes

its-darsh self-assigned this Jan 10, 2026

its-darsh added enhancement New feature or request on hold On hold, usually in wait for a PR to be merged. or something... help wanted Extra attention is needed labels Jan 10, 2026

its-darsh requested changes Jan 11, 2026

View reviewed changes

amansxcalibur force-pushed the main branch from feab9b3 to 45159c3 Compare January 13, 2026 20:30

amansxcalibur force-pushed the main branch from 5269c89 to d7408b8 Compare April 8, 2026 12:28

amansxcalibur closed this Apr 8, 2026

amansxcalibur force-pushed the main branch from d7408b8 to 7809cc8 Compare April 8, 2026 12:34

amansxcalibur added 6 commits April 10, 2026 13:36

feat: implement CircularScale

a67de47

chore: add CircularScale examples

28b3b07

chore: add type hints and return types

d2a8a5b

fix: add inefficient style class support

1052314

chore: add typing and refactor

2641f59

fix: add style class checks to CircularScale gadgets before re-buil…

a5b659b

…ding its `WidgetPath`

its-darsh reopened this Apr 10, 2026

fix: cache CircularScale style lookups in a dictionary for faster d…

f0b59d0

…raw cycles

refactor: move CircularScale's cached styles to TypedDict

1178132

its-darsh merged commit 23cab85 into Fabric-Development:main Apr 17, 2026



		class CircularScale(CircularProgressBar):
		NON_ROUND_CAP_DELTA = 0.01

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amansxcalibur commented Jan 9, 2026

Features

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