From cd885ce7c59e6493c45bf0a73604379d631ffa48 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 3 Sep 2016 17:17:54 +0900
Subject: [PATCH] ui: Add SetCursorVisibility (#258)

---
 internal/ui/ui_glfw.go   | 14 ++++++++++++++
 internal/ui/ui_js.go     |  8 ++++++++
 internal/ui/ui_mobile.go |  4 ++++
 run.go                   |  7 +++++++
 4 files changed, 33 insertions(+)

diff --git a/internal/ui/ui_glfw.go b/internal/ui/ui_glfw.go
index 94b7b3391..ab86732e7 100644
--- a/internal/ui/ui_glfw.go
+++ b/internal/ui/ui_glfw.go
@@ -142,6 +142,20 @@ func ScreenScale() float64 {
 	return s
 }
 
+func SetCursorVisibility(visible bool) {
+	// This can be called before Run: change the state asyncly.
+	go func() {
+		_ = currentUI.runOnMainThread(func() error {
+			c := glfw.CursorNormal
+			if !visible {
+				c = glfw.CursorHidden
+			}
+			currentUI.window.SetInputMode(glfw.CursorMode, c)
+			return nil
+		})
+	}()
+}
+
 func Run(width, height int, scale float64, title string, g GraphicsContext) error {
 	u := currentUI
 	// GLContext must be created before setting the screen size, which requires
diff --git a/internal/ui/ui_js.go b/internal/ui/ui_js.go
index e583ef97c..633831be7 100644
--- a/internal/ui/ui_js.go
+++ b/internal/ui/ui_js.go
@@ -57,6 +57,14 @@ func ScreenScale() float64 {
 	return currentUI.scale
 }
 
+func SetCursorVisibility(visibility bool) {
+	if visibility {
+		canvas.Get("style").Set("cursor", "auto")
+	} else {
+		canvas.Get("style").Set("cursor", "none")
+	}
+}
+
 func (u *userInterface) actualScreenScale() float64 {
 	return u.scale * u.deviceScale
 }
diff --git a/internal/ui/ui_mobile.go b/internal/ui/ui_mobile.go
index 7ad596c02..cfbce3eda 100644
--- a/internal/ui/ui_mobile.go
+++ b/internal/ui/ui_mobile.go
@@ -112,6 +112,10 @@ func ScreenScale() float64 {
 	return currentUI.scale
 }
 
+func SetCursorVisibility(visibility bool) {
+	// Do nothing
+}
+
 func (u *userInterface) actualScreenScale() float64 {
 	return u.scale * deviceScale()
 }
diff --git a/run.go b/run.go
index fe5d3ab25..19ad428f1 100644
--- a/run.go
+++ b/run.go
@@ -153,3 +153,10 @@ func ScreenScale() float64 {
 	}
 	return ui.ScreenScale()
 }
+
+// SetCursorVisibility changes the state of cursor visiblity.
+//
+// This function is concurrent-safe.
+func SetCursorVisibility(visible bool) {
+	ui.SetCursorVisibility(visible)
+}