fixes Hover and some coding style

Author: Drakirus

README.md

@@ -49,6 +49,7 @@ It's also possible to [manually install](https://github.com/go-flutter-desktop/g
   - <kbd>Right</kbd>  <kbd>ctrl-Right</kbd>  <kbd>ctrl-shift-Right</kbd>
   - <kbd>Backspace</kbd>  <kbd>ctrl-Backspace</kbd> <kbd>Delete</kbd>
 - Mouse-over/hovering
+- Mouse-buttons
 - RawKeyboard events (through `RawKeyEventDataLinux` regardless of the platform)
 
 Are you missing a feature? [Open an issue!](https://github.com/go-flutter-desktop/go-flutter/issues/new)

embedder/embedder.go

@@ -143,16 +143,14 @@ const (
 	PointerPhaseHover  PointerPhase = C.kHover
 )
 
-// PointerPhase corresponds to the C.enum describing phase of the mouse pointer.
+// PointerButtonMouse corresponds to the C.enum describing the mouse buttons.
 type PointerButtonMouse int64
 
 // Values representing the mouse buttons.
 const (
 	PointerButtonMousePrimary   PointerButtonMouse = C.kFlutterPointerButtonMousePrimary
 	PointerButtonMouseSecondary PointerButtonMouse = C.kFlutterPointerButtonMouseSecondary
 	PointerButtonMouseMiddle    PointerButtonMouse = C.kFlutterPointerButtonMouseMiddle
-	PointerButtonMouseBack      PointerButtonMouse = C.kFlutterPointerButtonMouseBack
-	PointerButtonMouseForward   PointerButtonMouse = C.kFlutterPointerButtonMouseForward
 )
 
 // PointerSignalKind corresponds to the C.enum describing signal kind of the mouse pointer.

glfw.go

@@ -117,28 +117,29 @@ func (m *windowManager) glfwCursorPosCallback(window *glfw.Window, x, y float64)
 func (m *windowManager) handleButtonPhase(window *glfw.Window, action glfw.Action, buttons embedder.PointerButtonMouse) {
 	if action == glfw.Press {
 		m.pointerButton |= buttons
-		// If only one button is pressed then each bits of buttons will be equals to m.pointerButton
-		// 2019-06-18, FlutterPointerPhase with mouse
-		// Refer to (https://github.com/flutter/engine/blob/master/shell/platform/embedder/embedder.h#L280-L314)
+		// If only one button is pressed then each bits of buttons will be equals
+		// to m.pointerButton.
 		if m.pointerButton == buttons {
 			m.sendPointerEventButton(window, embedder.PointerPhaseDown)
 		} else {
+			// if any other buttons are already pressed when a new button is pressed,
+			// the engine is expecting a Move phase instead of a Down phase.
 			m.sendPointerEventButton(window, embedder.PointerPhaseMove)
 		}
 		m.pointerPhase = embedder.PointerPhaseMove
 	}
 
 	if action == glfw.Release {
 		m.pointerButton ^= buttons
-		// If all button are released then m.pointerButton will be equals to 0
-		// 2019-06-18, FlutterPointerPhase with mouse
-		// Refer to (https://github.com/flutter/engine/blob/master/shell/platform/embedder/embedder.h#L280-L314)
+		// If all button are released then m.pointerButton is cleared
 		if m.pointerButton == 0 {
 			m.sendPointerEventButton(window, embedder.PointerPhaseUp)
+			m.pointerPhase = embedder.PointerPhaseHover
 		} else {
+			// if any other buttons are still pressed when one button is released
+			// the engine is expecting a Move phase instead of a Up phase.
 			m.sendPointerEventButton(window, embedder.PointerPhaseMove)
 		}
-		m.pointerPhase = embedder.PointerPhaseHover
 	}
 }