gesture: don't rely on Enter events to determine validity of click

We're about to not emit Enter and Leave events for touch input, and
this change changes the Click gesture to no longer rely on those
events to determine whether a Release is inside its bounds.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

gesture/gesture.go

@@ -78,7 +78,9 @@ type Click struct {
 	clicks int
 	// pressed tracks whether the pointer is pressed.
 	pressed bool
-	// entered tracks whether the pointer is inside the gesture.
+	// hovered tracks whether the pointer is inside the gesture.
+	hovered bool
+	// entered tracks whether an Enter event has been received.
 	entered bool
 	// pid is the pointer.ID.
 	pid pointer.ID
@@ -167,7 +169,7 @@ func (c *Click) Add(ops *op.Ops) {
 
 // Hovered returns whether a pointer is inside the area.
 func (c *Click) Hovered() bool {
-	return c.entered
+	return c.hovered
 }
 
 // Pressed returns whether a pointer is pressing.
@@ -189,7 +191,7 @@ func (c *Click) Events(q event.Queue) []ClickEvent {
 				break
 			}
 			c.pressed = false
-			if c.entered {
+			if !c.entered || c.hovered {
 				if e.Time-c.clickedAt < doubleClickDuration {
 					c.clicks++
 				} else {
@@ -203,6 +205,7 @@ func (c *Click) Events(q event.Queue) []ClickEvent {
 		case pointer.Cancel:
 			wasPressed := c.pressed
 			c.pressed = false
+			c.hovered = false
 			c.entered = false
 			if wasPressed {
 				events = append(events, ClickEvent{Type: TypeCancel})
@@ -214,7 +217,7 @@ func (c *Click) Events(q event.Queue) []ClickEvent {
 			if e.Source == pointer.Mouse && e.Buttons != pointer.ButtonPrimary {
 				break
 			}
-			if !c.entered {
+			if !c.hovered {
 				c.pid = e.PointerID
 			}
 			if c.pid != e.PointerID {
@@ -227,13 +230,14 @@ func (c *Click) Events(q event.Queue) []ClickEvent {
 				c.pid = e.PointerID
 			}
 			if c.pid == e.PointerID {
-				c.entered = false
+				c.hovered = false
 			}
 		case pointer.Enter:
 			if !c.pressed {
 				c.pid = e.PointerID
 			}
 			if c.pid == e.PointerID {
+				c.hovered = true
 				c.entered = true
 			}
 		}