Fix style panel opening when disabled (#1983)

Closes #1982

When choosing whether to disable the mobile style menu, we now also
check if the select tool is active and whether any shapes have been
selected.

### Change Type

- [x] `patch` — Bug fix
- [ ] `minor` — New feature
- [ ] `major` — Breaking change
- [ ] `dependencies` — Changes to package dependencies[^1]
- [ ] `documentation` — Changes to the documentation only[^2]
- [ ] `tests` — Changes to any test code only[^2]
- [ ] `internal` — Any other changes that don't affect the published
package[^2]
- [ ] I don't know

[^1]: publishes a `patch` release, for devDependencies use `internal`
[^2]: will not publish a new version

### Test Plan

1. On a small screen
2. Choose the select tool
3. Deselect all shapes
4. Click on the disabled style menu button

Expected: Nothing should happen
Actual: The style menu opens

### Release Notes

- When select tool is active, the style menu shouldn't be openable
unless a shape is also selected.

Before/After

<img width="300"
src="https://github.com/tldraw/tldraw/assets/98838967/91ea55c8-0fcc-4f73-b61e-565829a5f25e"
/>
<img width="300"
src="https://github.com/tldraw/tldraw/assets/98838967/ee4070fe-e236-4818-8fb4-43520210102b"
/>

---------

Co-authored-by: Steve Ruiz <steveruizok@gmail.com>

packages/tldraw/src/lib/ui/components/MobileStylePanel.tsx

@@ -1,5 +1,12 @@
-import { DefaultColorStyle, getDefaultColorTheme, useEditor, useValue } from '@tldraw/editor'
+import {
+	DefaultColorStyle,
+	TLDefaultColorStyle,
+	getDefaultColorTheme,
+	useEditor,
+	useValue,
+} from '@tldraw/editor'
 import { useCallback } from 'react'
+import { useRelevantStyles } from '../hooks/useRevelantStyles'
 import { useTranslation } from '../hooks/useTranslation/useTranslation'
 import { StylePanel } from './StylePanel/StylePanel'
 import { Button } from './primitives/Button'
@@ -10,17 +17,12 @@ export function MobileStylePanel() {
 	const editor = useEditor()
 	const msg = useTranslation()
 
-	const currentColor = useValue(
-		'current color',
-		() => {
-			const color = editor.sharedStyles.get(DefaultColorStyle)
-			if (!color) return 'var(--color-muted-1)'
-			if (color.type === 'mixed') return null
-			const theme = getDefaultColorTheme({ isDarkMode: editor.user.isDarkMode })
-			return theme[color.value].solid
-		},
-		[editor]
-	)
+	const relevantStyles = useRelevantStyles()
+	const color = relevantStyles?.styles.get(DefaultColorStyle)
+	const theme = getDefaultColorTheme({ isDarkMode: editor.user.isDarkMode })
+	const currentColor = (
+		color?.type === 'shared' ? theme[color.value as TLDefaultColorStyle] : theme.black
+	).solid
 
 	const disableStylePanel = useValue(
 		'isHandOrEraserToolActive',
@@ -43,10 +45,12 @@ export function MobileStylePanel() {
 				<Button
 					className="tlui-toolbar__tools__button tlui-toolbar__styles__button"
 					data-testid="mobile.styles"
-					style={{ color: currentColor ?? 'var(--color-text)' }}
+					style={{
+						color: disableStylePanel ? 'var(--color-muted-1)' : currentColor,
+					}}
 					title={msg('style-panel.title')}
 				>
-					<Icon icon={currentColor ? 'blob' : 'mixed'} />
+					<Icon icon={disableStylePanel ? 'blob' : color?.type === 'mixed' ? 'mixed' : 'blob'} />
 				</Button>
 			</PopoverTrigger>
 			<PopoverContent side="top" align="end">

packages/tldraw/src/lib/ui/components/StylePanel/StylePanel.tsx

@@ -8,18 +8,16 @@ import {
 	DefaultHorizontalAlignStyle,
 	DefaultSizeStyle,
 	DefaultVerticalAlignStyle,
-	Editor,
 	GeoShapeGeoStyle,
 	LineShapeSplineStyle,
 	ReadonlySharedStyleMap,
 	SharedStyle,
-	SharedStyleMap,
 	StyleProp,
 	minBy,
 	useEditor,
-	useValue,
 } from '@tldraw/editor'
 import React, { useCallback } from 'react'
+import { useRelevantStyles } from '../../hooks/useRevelantStyles'
 import { useTranslation } from '../../hooks/useTranslation/useTranslation'
 import { Button } from '../primitives/Button'
 import { ButtonPicker } from '../primitives/ButtonPicker'
@@ -32,28 +30,11 @@ interface StylePanelProps {
 	isMobile?: boolean
 }
 
-const selectToolStyles = [DefaultColorStyle, DefaultDashStyle, DefaultFillStyle, DefaultSizeStyle]
-function getRelevantStyles(
-	editor: Editor
-): { styles: ReadonlySharedStyleMap; opacity: SharedStyle<number> } | null {
-	const styles = new SharedStyleMap(editor.sharedStyles)
-	const hasShape = editor.selectedShapeIds.length > 0 || !!editor.root.current.value?.shapeType
-
-	if (styles.size === 0 && editor.isIn('select') && editor.selectedShapeIds.length === 0) {
-		for (const style of selectToolStyles) {
-			styles.applyValue(style, editor.getStyleForNextShape(style))
-		}
-	}
-
-	if (styles.size === 0 && !hasShape) return null
-	return { styles, opacity: editor.sharedOpacity }
-}
-
 /** @internal */
 export const StylePanel = function StylePanel({ isMobile }: StylePanelProps) {
 	const editor = useEditor()
 
-	const relevantStyles = useValue('getRelevantStyles', () => getRelevantStyles(editor), [editor])
+	const relevantStyles = useRelevantStyles()
 
 	const handlePointerOut = useCallback(() => {
 		if (!isMobile) {

packages/tldraw/src/lib/ui/hooks/useRevelantStyles.ts

@@ -0,0 +1,37 @@
+import {
+	DefaultColorStyle,
+	DefaultDashStyle,
+	DefaultFillStyle,
+	DefaultSizeStyle,
+	ReadonlySharedStyleMap,
+	SharedStyle,
+	SharedStyleMap,
+	useEditor,
+	useValue,
+} from '@tldraw/editor'
+
+const selectToolStyles = [DefaultColorStyle, DefaultDashStyle, DefaultFillStyle, DefaultSizeStyle]
+
+export function useRelevantStyles(): {
+	styles: ReadonlySharedStyleMap
+	opacity: SharedStyle<number>
+} | null {
+	const editor = useEditor()
+	return useValue(
+		'getRelevantStyles',
+		() => {
+			const styles = new SharedStyleMap(editor.sharedStyles)
+			const hasShape = editor.selectedShapeIds.length > 0 || !!editor.root.current.value?.shapeType
+
+			if (styles.size === 0 && editor.isIn('select') && editor.selectedShapeIds.length === 0) {
+				for (const style of selectToolStyles) {
+					styles.applyValue(style, editor.getStyleForNextShape(style))
+				}
+			}
+
+			if (styles.size === 0 && !hasShape) return null
+			return { styles, opacity: editor.sharedOpacity }
+		},
+		[editor]
+	)
+}