feat: add Reading Pane at Bottom mail layout #262

components/layout/resize-handle.tsx

@@ -8,38 +8,46 @@ interface ResizeHandleProps {
   onResize: (delta: number) => void;
   onResizeEnd?: () => void;
   onDoubleClick?: () => void;
+  orientation?: "vertical" | "horizontal";
   className?: string;
 }
 
 const KEYBOARD_STEP = 10;
 
-export function ResizeHandle({ onResizeStart, onResize, onResizeEnd, onDoubleClick, className }: ResizeHandleProps) {
+export function ResizeHandle({ onResizeStart, onResize, onResizeEnd, onDoubleClick, orientation = "vertical", className }: ResizeHandleProps) {
   const isDragging = useRef(false);
-  const startX = useRef(0);
+  const startPos = useRef(0);
+  const isHorizontal = orientation === "horizontal";
 
   const handleMouseDown = useCallback((e: React.MouseEvent) => {
     e.preventDefault();
     isDragging.current = true;
-    startX.current = e.clientX;
-    document.body.style.cursor = "col-resize";
+    startPos.current = isHorizontal ? e.clientY : e.clientX;
+    document.body.style.cursor = isHorizontal ? "row-resize" : "col-resize";
     document.body.style.userSelect = "none";
     onResizeStart?.();
-  }, [onResizeStart]);
+  }, [onResizeStart, isHorizontal]);
 
   const handleKeyDown = useCallback((e: React.KeyboardEvent) => {
     let delta = 0;
-    if (e.key === "ArrowLeft") delta = -KEYBOARD_STEP;
-    else if (e.key === "ArrowRight") delta = KEYBOARD_STEP;
-    else return;
+    if (isHorizontal) {
+      if (e.key === "ArrowUp") delta = -KEYBOARD_STEP;
+      else if (e.key === "ArrowDown") delta = KEYBOARD_STEP;
+      else return;
+    } else {
+      if (e.key === "ArrowLeft") delta = -KEYBOARD_STEP;
+      else if (e.key === "ArrowRight") delta = KEYBOARD_STEP;
+      else return;
+    }
     e.preventDefault();
     onResize(delta);
     onResizeEnd?.();
-  }, [onResize, onResizeEnd]);
+  }, [onResize, onResizeEnd, isHorizontal]);
 
   useEffect(() => {
     const handleMouseMove = (e: MouseEvent) => {
       if (!isDragging.current) return;
-      const delta = e.clientX - startX.current;
+      const delta = (isHorizontal ? e.clientY : e.clientX) - startPos.current;
       onResize(delta);
     };
 
@@ -57,24 +65,25 @@ export function ResizeHandle({ onResizeStart, onResize, onResizeEnd, onDoubleCli
       document.removeEventListener("mousemove", handleMouseMove);
       document.removeEventListener("mouseup", handleMouseUp);
     };
-  }, [onResize, onResizeEnd]);
+  }, [onResize, onResizeEnd, isHorizontal]);
 
   return (
     <div
       role="separator"
-      aria-orientation="vertical"
+      aria-orientation={isHorizontal ? "horizontal" : "vertical"}
       aria-label="Resize"
       tabIndex={0}
       onMouseDown={handleMouseDown}
       onKeyDown={handleKeyDown}
       onDoubleClick={onDoubleClick}
       className={cn(
-        "w-1 flex-shrink-0 cursor-col-resize hover:bg-primary/30 active:bg-primary/50 transition-colors relative group",
+        "flex-shrink-0 hover:bg-primary/30 active:bg-primary/50 transition-colors relative group",
         "focus-visible:outline-none focus-visible:bg-primary/40 focus-visible:ring-2 focus-visible:ring-primary/50",
+        isHorizontal ? "h-1 cursor-row-resize bg-border" : "w-1 cursor-col-resize",
         className
       )}
     >
-      <div className="absolute inset-y-0 -left-1 -right-1" />
+      <div className={cn("absolute", isHorizontal ? "inset-x-0 -top-1 -bottom-1" : "inset-y-0 -left-1 -right-1")} />
     </div>
   );
 }