Fix issue with cursor not chaning in openGL mode.

Author: treeform

src/fidget/common.nim

@@ -161,6 +161,7 @@ type
     pixelScale*: float32
     wheelDelta*: float32
     cursorStyle*: MouseCursorStyle ## Sets the mouse cursor icon
+    prevCursorStyle*: MouseCursorStyle
 
   Keyboard* = ref object
     state*: KeyState

src/fidget/htmlbackend.nim

@@ -362,7 +362,6 @@ proc draw*(index: int, node: Node, parent: Node) =
     draw(i, n, node)
 
 var startTime: float
-var prevMouseCursorStyle: MouseCursorStyle
 
 proc drawStart() =
   startTime = dom.window.performance.now()
@@ -443,8 +442,8 @@ proc drawFinish() =
   # echo perf.numLowLevelCalls
 
   # Only set mouse style when it changes.
-  if prevMouseCursorStyle != mouse.cursorStyle:
-    prevMouseCursorStyle = mouse.cursorStyle
+  if mouse.prevCursorStyle != mouse.cursorStyle:
+    mouse.prevCursorStyle = mouse.cursorStyle
     case mouse.cursorStyle:
       of Default:
         rootDomNode.style.cursor = "default"

src/fidget/opengl/base.nim

@@ -41,6 +41,16 @@ var
   frameCount*, tickCount*: int
   lastDraw, lastTick: int64
 
+var
+  cursorDefault*: CursorHandle
+  cursorPointer*: CursorHandle
+  cursorGrab*: CursorHandle
+  cursorNSResize*: CursorHandle
+
+proc setCursor*(cursor: CursorHandle) =
+  echo "set cursor"
+  window.setCursor(cursor)
+
 proc updateWindowSize() =
   requestedFrame = true
 
@@ -335,6 +345,11 @@ proc start*(openglVersion: (int, int), msaa: MSAA, mainLoopMode: MainLoopMode) =
 
   window.makeContextCurrent()
 
+  cursorDefault = createStandardCursor(ARROW_CURSOR)
+  cursorPointer = createStandardCursor(HAND_CURSOR)
+  cursorGrab = createStandardCursor(HAND_CURSOR)
+  cursorNSResize = createStandardCursor(HRESIZE_CURSOR)
+
   when not defined(emscripten):
     swapInterval(1)
     # Load OpenGL

src/fidget/openglbackend.nim

@@ -306,6 +306,8 @@ proc setupFidget(
     ctx.saveTransform()
     ctx.scale(ctx.pixelScale)
 
+    mouse.cursorStyle = Default
+
     setupRoot()
     root.box.x = float 0
     root.box.y = float 0
@@ -330,6 +332,20 @@ proc setupFidget(
     ctx.restoreTransform()
     ctx.endFrame()
 
+    # Only set mouse style when it changes.
+    if mouse.prevCursorStyle != mouse.cursorStyle:
+      mouse.prevCursorStyle = mouse.cursorStyle
+      echo mouse.cursorStyle
+      case mouse.cursorStyle:
+        of Default:
+          setCursor(cursorDefault)
+        of Pointer:
+          setCursor(cursorPointer)
+        of Grab:
+          setCursor(cursorGrab)
+        of NSResize:
+          setCursor(cursorNSResize)
+
     when defined(testOneFrame):
       ## This is used for test only
       ## Take a screen shot of the first frame and exit.

tests/cursorstyle/cursorstyle.nim

@@ -0,0 +1,13 @@
+## Test the mouse cursor changing when you hover over an element.
+
+import fidget
+
+proc drawMain() =
+  rectangle "example":
+    box 100, 100, 100, 100
+    fill "#FF0000"
+    onHover:
+      fill "#00FF00"
+      mouse.cursorStyle = Pointer
+
+startFidget(drawMain, w = 400, h = 400)

tests/cursorstyle/screenshot.png

@@ -146,6 +146,7 @@ proc main(
   runList.add "tests/textalignexpand"
   runList.add "tests/textalignfixed"
   runList.add "tests/textandinputs"
+  runList.add "tests/cursorstyle"
 
   runList.add "examples/areas"
   runList.add "examples/demo"