feat(mouse): add shift press support

Support parsing shift key press

mouse.go

@@ -13,11 +13,12 @@ type MouseMsg MouseEvent
 // MouseEvent represents a mouse event, which could be a click, a scroll wheel
 // movement, a cursor movement, or a combination.
 type MouseEvent struct {
-	X    int
-	Y    int
-	Type MouseEventType
-	Alt  bool
-	Ctrl bool
+	X     int
+	Y     int
+	Type  MouseEventType
+	Shift bool
+	Alt   bool
+	Ctrl  bool
 }
 
 // String returns a string representation of a mouse event.
@@ -28,6 +29,9 @@ func (m MouseEvent) String() (s string) {
 	if m.Alt {
 		s += "alt+"
 	}
+	if m.Shift {
+		s += "shift+"
+	}
 	s += mouseEventTypes[m.Type]
 	return s
 }
@@ -131,12 +135,9 @@ func parseX10MouseEvents(buf []byte) ([]MouseEvent, error) {
 			}
 		}
 
-		if e&bitAlt != 0 {
-			m.Alt = true
-		}
-		if e&bitCtrl != 0 {
-			m.Ctrl = true
-		}
+		m.Shift = e&bitShift != 0
+		m.Alt = e&bitAlt != 0
+		m.Ctrl = e&bitCtrl != 0
 
 		// (1,1) is the upper left. We subtract 1 to normalize it to (0,0).
 		m.X = int(v[1]) - byteOffset - 1

mouse_test.go

@@ -48,6 +48,23 @@ func TestMouseEvent_String(t *testing.T) {
 			event:    MouseEvent{Type: MouseMotion},
 			expected: "motion",
 		},
+		{
+			name: "shift+left",
+			event: MouseEvent{
+				Type:  MouseLeft,
+				Shift: true,
+			},
+			expected: "shift+left",
+		},
+		{
+			name: "ctrl+shift+left",
+			event: MouseEvent{
+				Type:  MouseLeft,
+				Shift: true,
+				Ctrl:  true,
+			},
+			expected: "ctrl+shift+left",
+		},
 		{
 			name: "alt+left",
 			event: MouseEvent{
@@ -73,6 +90,16 @@ func TestMouseEvent_String(t *testing.T) {
 			},
 			expected: "ctrl+alt+left",
 		},
+		{
+			name: "ctrl+alt+shift+left",
+			event: MouseEvent{
+				Type:  MouseLeft,
+				Alt:   true,
+				Ctrl:  true,
+				Shift: true,
+			},
+			expected: "ctrl+alt+shift+left",
+		},
 		{
 			name: "ignore coordinates",
 			event: MouseEvent{