feat: configurable message list width

Signed-off-by: Sebastian <krupinski01@gmail.com>

src/stores/mailSettingsStore.ts

@@ -6,11 +6,13 @@ const MESSAGE_READ_ENABLED_KEY = 'mail.behaviour.messageReadEnabled'
 const MESSAGE_READ_DELAY_KEY = 'mail.behaviour.messageReadDelay'
 const FOLDER_VIEW_MODE_KEY = 'mail.folderViewMode'
 const MESSAGE_LIST_DENSITY_KEY = 'mail.messageListDensity'
+const MESSAGE_LIST_WIDTH_KEY = 'mail.messageListWidth'
 
 const DEFAULT_MESSAGE_READ_ENABLED = false
 const DEFAULT_MESSAGE_READ_DELAY = 5
 const DEFAULT_FOLDER_VIEW_MODE = 'tree'
 const DEFAULT_MESSAGE_LIST_DENSITY = 'cozy'
+const DEFAULT_MESSAGE_LIST_WIDTH = 35
 
 export type FolderViewMode = 'tree' | 'page'
 
@@ -33,6 +35,16 @@ export const messageListDensityConfig: Record<MessageListDensity, {
   comfortable: { itemHeight: 96, lines: 'three', showSubjectLine: true, showThirdLine: true },
 }
 
+// Width of the message list panel, as a percentage of the split area. Only applies to
+// the side-by-side (vertical reading pane) view; future layout views own their own sizing.
+export type MessageListWidth = 25 | 35 | 50
+
+export const messageListWidthOptions = [
+  { value: 25, title: 'Narrow' },
+  { value: 35, title: 'Medium' },
+  { value: 50, title: 'Wide' },
+]
+
 export const messageReadDelayOptions = [
   { value: 2, title: '2 seconds' },
   { value: 5, title: '5 seconds' },
@@ -67,6 +79,10 @@ function normalizeMessageListDensity(value: unknown, fallback: MessageListDensit
   return value === 'compact' || value === 'cozy' || value === 'comfortable' ? value : fallback
 }
 
+function normalizeMessageListWidth(value: unknown, fallback: MessageListWidth): MessageListWidth {
+  return value === 25 || value === 35 || value === 50 ? value : fallback
+}
+
 export const useMailSettingsStore = defineStore('mailSettingsStore', () => {
   const userStore = useUserStore()
 
@@ -99,9 +115,18 @@ export const useMailSettingsStore = defineStore('mailSettingsStore', () => {
     ),
   })
 
+  const messageListWidth = computed({
+    get: () => normalizeMessageListWidth(userStore.getSetting(MESSAGE_LIST_WIDTH_KEY), DEFAULT_MESSAGE_LIST_WIDTH),
+    set: (value: MessageListWidth) => userStore.setSetting(
+      MESSAGE_LIST_WIDTH_KEY,
+      normalizeMessageListWidth(value, DEFAULT_MESSAGE_LIST_WIDTH),
+    ),
+  })
+
   return {
     folderViewMode,
     messageListDensity,
+    messageListWidth,
     messageReadEnabled,
     messageReadDelay,
   }