mouse: track buttons independently (#1416)

Keep left-button selection state until its own release so right-click
interactions do not interrupt dragging.

packages/core/src/lib/parse.mouse.test.ts

@@ -380,19 +380,12 @@ describe("MouseParser SGR mode", () => {
       expect(move.type).toBe("move")
     })
 
-    test("multiple buttons pressed — any motion is drag", () => {
+    test("releasing one of multiple pressed buttons keeps motion dragging", () => {
       parser.parseMouseEvent(encodeSGR(0, 5, 5, true)) // left down
       parser.parseMouseEvent(encodeSGR(2, 5, 5, true)) // right down
-      const e = parser.parseMouseEvent(encodeSGR(32, 8, 5, false))!
-      expect(e.type).toBe("drag")
-    })
-
-    test("release clears ALL tracked buttons", () => {
-      parser.parseMouseEvent(encodeSGR(0, 5, 5, true)) // left down
-      parser.parseMouseEvent(encodeSGR(2, 5, 5, true)) // right down
-      parser.parseMouseEvent(encodeSGR(0, 5, 5, false)) // release (clears all)
-      const e = parser.parseMouseEvent(encodeSGR(32, 8, 5, false))!
-      expect(e.type).toBe("move") // no buttons tracked → move, not drag
+      parser.parseMouseEvent(encodeSGR(2, 5, 5, false)) // right up
+      const event = parser.parseMouseEvent(encodeSGR(32, 8, 5, false))!
+      expect(event.type).toBe("drag")
     })
 
     test("reset() clears button tracking state", () => {

packages/core/src/lib/parse.mouse.ts

@@ -175,7 +175,7 @@ export class MouseParser {
       if (type === "down" && button !== 3) {
         this.mouseButtonsPressed.add(button)
       } else if (type === "up") {
-        this.mouseButtonsPressed.clear()
+        this.mouseButtonsPressed.delete(button)
       }
     }
 

packages/core/src/renderer.ts

@@ -3630,7 +3630,7 @@ export class CliRenderer extends EventEmitter implements RenderContext {
       return true
     }
 
-    if (mouseEvent.type === "up" && this.currentSelection?.isDragging) {
+    if (mouseEvent.type === "up" && mouseEvent.button === MouseButton.LEFT && this.currentSelection?.isDragging) {
       if (maybeRenderable) {
         const event = new MouseEvent(maybeRenderable, {
           ...mouseEvent,
@@ -3716,7 +3716,12 @@ export class CliRenderer extends EventEmitter implements RenderContext {
       this.lastOverRenderable = undefined
     }
 
-    if (!event?.defaultPrevented && mouseEvent.type === "down" && this.currentSelection) {
+    if (
+      !event?.defaultPrevented &&
+      mouseEvent.type === "down" &&
+      mouseEvent.button === MouseButton.LEFT &&
+      this.currentSelection
+    ) {
       this.clearSelection()
     }
 

packages/core/src/tests/renderer.mouse.test.ts

@@ -343,7 +343,7 @@ describe("renderer handleMouseData", () => {
     }
   })
 
-  test("selection drag marks events as dragging and ends on mouse up", async () => {
+  test("selection drag ignores right-button release and ends on left mouse up", async () => {
     try {
       const target = new TestRenderable(renderer, {
         id: "selectable",
@@ -372,7 +372,11 @@ describe("renderer handleMouseData", () => {
       const endY = target.y + 3
 
       await mockMouse.pressDown(startX, startY)
+      await mockMouse.click(startX, startY, MouseButtons.RIGHT)
+      expect(renderer.getSelection()?.isDragging).toBe(true)
+
       await mockMouse.moveTo(endX, endY)
+      expect(renderer.getSelection()?.focus).toEqual({ x: endX, y: endY })
       await mockMouse.release(endX, endY)
 
       expect(renderer.hasSelection).toBe(true)