feat(terminal): refactor font size handling in terminal settings

- Updated terminal font size management to use a delta approach, allowing for dynamic adjustments based on user interactions.
- Introduced new utility functions for increasing, decreasing, and resetting font size deltas.
- Modified relevant components and hooks to accommodate the new font size delta logic, ensuring consistent font size rendering across the application.
- Updated type definitions and default settings to include font size delta in terminal configurations.

src-tauri/src/config/settings/terminal.rs

@@ -52,6 +52,8 @@ pub struct TerminalSettings {
     #[serde(default = "default_keep_alive")]
     pub keep_alive_interval: u32,
     #[serde(default)]
+    pub font_size_delta: f64,
+    #[serde(default)]
     pub x11_display: String,
     #[serde(default = "default_false")]
     pub hardware_acceleration: bool,
@@ -91,6 +93,7 @@ impl Default for TerminalSettings {
         Self {
             scrollback_lines: default_scrollback(),
             keep_alive_interval: default_keep_alive(),
+            font_size_delta: 0.0,
             x11_display: String::new(),
             hardware_acceleration: false,
             keyword_highlights_enabled: false,

src/components/layout/Header.tsx

@@ -49,9 +49,9 @@ import { invoke } from "@/lib/invoke";
 import { logger } from "@/lib/logger";
 import { isMacOS } from "@/lib/platform";
 import {
-  DEFAULT_TERMINAL_FONT_SIZE,
-  decreaseTerminalFontSize,
-  increaseTerminalFontSize,
+  decreaseTerminalFontSizeDelta,
+  increaseTerminalFontSizeDelta,
+  resetTerminalFontSizeDelta,
 } from "@/lib/terminalFontSize";
 import { getActivePane, getTabDisplayName } from "@/lib/workspaceTabs";
 import type { SavedConnection, Tab } from "@/types/global";
@@ -208,19 +208,25 @@ export default function Header({
 
   const handleZoom = (delta: number) => {
     updateAppSettings((prev) => ({
-      appearance: {
-        ...prev.appearance,
-        font_size:
+      terminal: {
+        ...prev.terminal,
+        font_size_delta:
           delta > 0
-            ? increaseTerminalFontSize(prev.appearance.font_size)
-            : decreaseTerminalFontSize(prev.appearance.font_size),
+            ? increaseTerminalFontSizeDelta(
+                prev.appearance.font_size,
+                prev.terminal.font_size_delta,
+              )
+            : decreaseTerminalFontSizeDelta(
+                prev.appearance.font_size,
+                prev.terminal.font_size_delta,
+              ),
       },
     }));
   };
 
   const handleResetZoom = () =>
     updateAppSettings((prev) => ({
-      appearance: { ...prev.appearance, font_size: DEFAULT_TERMINAL_FONT_SIZE },
+      terminal: { ...prev.terminal, font_size_delta: resetTerminalFontSizeDelta() },
     }));
 
   const menuKeys = [

src/components/terminal/XTerminal.tsx

@@ -48,6 +48,7 @@ import {
 } from "@/lib/shortcutRegistry";
 import { registerTerminalContextProvider } from "@/lib/terminalContext";
 import { getTerminalDropOverlayCopy, handleTerminalFileDrop } from "@/lib/terminalFileDrop";
+import { resolveTerminalFontSize } from "@/lib/terminalFontSize";
 import {
   applyTerminalInputData,
   applyTerminalInputPreview,
@@ -405,7 +406,7 @@ export default function XTerminal({
       scrollback: terminalSettings.scrollback_lines,
       cursorBlink: appearance.cursor_blink,
       cursorStyle: appearance.cursor_style as "block" | "underline" | "bar",
-      fontSize: appearance.font_size,
+      fontSize: resolveTerminalFontSize(appearance.font_size, terminalSettings.font_size_delta),
       fontFamily: appearance.font_family,
       minimumContrastRatio: appearance.minimum_contrast_ratio,
       wordSeparator: interaction.word_separators,

src/context/AppContext.tsx

@@ -236,6 +236,7 @@ const DEFAULT_APP_SETTINGS: AppSettings = {
   terminal: {
     scrollback_lines: 10000,
     keep_alive_interval: 60,
+    font_size_delta: 0,
     x11_display: "",
     hardware_acceleration: false,
     keyword_highlights_enabled: false,

src/context/ChildAppProvider.tsx

@@ -62,6 +62,7 @@ const DEFAULT_APP_SETTINGS: AppSettings = {
   terminal: {
     scrollback_lines: 10000,
     keep_alive_interval: 60,
+    font_size_delta: 0,
     x11_display: "",
     hardware_acceleration: false,
     keyword_highlights_enabled: false,

src/hooks/useTerminalSettings.ts

@@ -3,6 +3,7 @@ import { WebglAddon } from "@xterm/addon-webgl";
 import type { Terminal } from "@xterm/xterm";
 import { useCallback, useEffect, useRef } from "react";
 import { isTerminalTransparencyEnabled } from "@/lib/backgroundImage";
+import { resolveTerminalFontSize } from "@/lib/terminalFontSize";
 import type { TerminalColors } from "@/lib/themes";
 import { installMacImeCompatibilityPatch } from "@/lib/xtermMacImeCompatibility";
 import type { AppSettings } from "@/types/global";
@@ -95,7 +96,10 @@ export function useTerminalSettings(
     if (terminalRef.current) {
       const options = terminalRef.current.options;
       options.fontFamily = appearance.font_family;
-      options.fontSize = appearance.font_size;
+      options.fontSize = resolveTerminalFontSize(
+        appearance.font_size,
+        terminalSettings.font_size_delta,
+      );
       options.cursorBlink = appearance.cursor_blink;
       options.cursorStyle = appearance.cursor_style as "block" | "underline" | "bar";
       options.minimumContrastRatio = appearance.minimum_contrast_ratio;
@@ -106,7 +110,13 @@ export function useTerminalSettings(
         requestAnimationFrame(() => fitAddonRef.current?.fit());
       }
     }
-  }, [appearance, terminalRef, fitAddonRef, scheduleTextureRefresh]);
+  }, [
+    appearance,
+    terminalSettings.font_size_delta,
+    terminalRef,
+    fitAddonRef,
+    scheduleTextureRefresh,
+  ]);
 
   // React to terminal core settings changes: scrollback
   useEffect(() => {

src/hooks/useTerminalZoom.ts

@@ -2,9 +2,9 @@ import { useCallback, useEffect, useRef } from "react";
 import { resolveShortcutKeys } from "@/hooks/useShortcutMap";
 import { matchesKeyEvent } from "@/lib/shortcutRegistry";
 import {
-  DEFAULT_TERMINAL_FONT_SIZE,
-  decreaseTerminalFontSize,
-  increaseTerminalFontSize,
+  decreaseTerminalFontSizeDelta,
+  increaseTerminalFontSizeDelta,
+  resetTerminalFontSizeDelta,
 } from "@/lib/terminalFontSize";
 import type { AppSettings } from "@/types/global";
 
@@ -22,25 +22,31 @@ export function useTerminalZoom(
 
   const handleZoomIn = useCallback(() => {
     updateAppSettings((prev) => ({
-      appearance: {
-        ...prev.appearance,
-        font_size: increaseTerminalFontSize(prev.appearance.font_size),
+      terminal: {
+        ...prev.terminal,
+        font_size_delta: increaseTerminalFontSizeDelta(
+          prev.appearance.font_size,
+          prev.terminal.font_size_delta,
+        ),
       },
     }));
   }, [updateAppSettings]);
 
   const handleZoomOut = useCallback(() => {
     updateAppSettings((prev) => ({
-      appearance: {
-        ...prev.appearance,
-        font_size: decreaseTerminalFontSize(prev.appearance.font_size),
+      terminal: {
+        ...prev.terminal,
+        font_size_delta: decreaseTerminalFontSizeDelta(
+          prev.appearance.font_size,
+          prev.terminal.font_size_delta,
+        ),
       },
     }));
   }, [updateAppSettings]);
 
   const handleResetZoom = useCallback(() => {
     updateAppSettings((prev) => ({
-      appearance: { ...prev.appearance, font_size: DEFAULT_TERMINAL_FONT_SIZE },
+      terminal: { ...prev.terminal, font_size_delta: resetTerminalFontSizeDelta() },
     }));
   }, [updateAppSettings]);
 

src/lib/terminalFontSize.ts

@@ -7,6 +7,26 @@ export function clampTerminalFontSize(fontSize: number): number {
   return Math.max(MIN_TERMINAL_FONT_SIZE, Math.min(MAX_TERMINAL_FONT_SIZE, Math.round(fontSize)));
 }
 
+export function resolveTerminalFontSize(baseFontSize: number, fontSizeDelta = 0): number {
+  return clampTerminalFontSize(baseFontSize + fontSizeDelta);
+}
+
+export function increaseTerminalFontSizeDelta(baseFontSize: number, fontSizeDelta = 0): number {
+  return (
+    resolveTerminalFontSize(baseFontSize, fontSizeDelta + TERMINAL_FONT_SIZE_STEP) - baseFontSize
+  );
+}
+
+export function decreaseTerminalFontSizeDelta(baseFontSize: number, fontSizeDelta = 0): number {
+  return (
+    resolveTerminalFontSize(baseFontSize, fontSizeDelta - TERMINAL_FONT_SIZE_STEP) - baseFontSize
+  );
+}
+
+export function resetTerminalFontSizeDelta(): number {
+  return 0;
+}
+
 export function increaseTerminalFontSize(fontSize: number): number {
   return clampTerminalFontSize(fontSize + TERMINAL_FONT_SIZE_STEP);
 }

src/types/global.d.ts

@@ -565,6 +565,7 @@ export type KeywordHighlightBuiltinRuleSettings = Record<string, boolean>;
 export interface TerminalSettings {
   scrollback_lines: number;
   keep_alive_interval: number;
+  font_size_delta: number;
   x11_display?: string;
   hardware_acceleration: boolean;
   keyword_highlights_enabled: boolean;