Add puglSetCursor()

8 files changed, 216 insertions, 2 deletions

diff --git a/pugl/detail/mac.h b/pugl/detail/mac.h
index b38dcd3..296faeb 100644
--- a/pugl/detail/mac.h
+++ b/pugl/detail/mac.h
@@ -61,6 +61,8 @@ struct PuglInternalsImpl {
 	NSApplication*   app;
 	PuglWrapperView* wrapperView;
 	NSView*          drawView;
+	NSCursor*        cursor;
 	PuglWindow*      window;
 	uint32_t         mods;
+	bool             mouseTracked;
 };
diff --git a/pugl/detail/mac.m b/pugl/detail/mac.m
index da9de20..3bf7cdf 100644
--- a/pugl/detail/mac.m
+++ b/pugl/detail/mac.m
@@ -343,11 +343,15 @@ handleCrossing(PuglWrapperView* view, NSEvent* event, const PuglEventType type)
 - (void) mouseEntered:(NSEvent*)event
 {
 	handleCrossing(self, event, PUGL_POINTER_IN);
+	[puglview->impl->cursor set];
+	puglview->impl->mouseTracked = true;
 }
 
 - (void) mouseExited:(NSEvent*)event
 {
+	[[NSCursor arrowCursor] set];
 	handleCrossing(self, event, PUGL_POINTER_OUT);
+	puglview->impl->mouseTracked = false;
 }
 
 - (void) mouseMoved:(NSEvent*)event
@@ -807,7 +811,11 @@ puglGetNativeWorld(PuglWorld* PUGL_UNUSED(world))
 PuglInternals*
 puglInitViewInternals(void)
 {
-	return (PuglInternals*)calloc(1, sizeof(PuglInternals));
+	PuglInternals* impl = (PuglInternals*)calloc(1, sizeof(PuglInternals));
+
+	impl->cursor = [NSCursor arrowCursor];
+
+	return impl;
 }
 
 static NSLayoutConstraint*
@@ -1309,6 +1317,47 @@ puglGetClipboard(PuglView* const    view,
 	return puglGetInternalClipboard(view, type, len);
 }
 
+static NSCursor*
+puglGetNsCursor(const PuglCursor cursor)
+{
+	switch (cursor) {
+	case PUGL_CURSOR_ARROW:
+		return [NSCursor arrowCursor];
+	case PUGL_CURSOR_CARET:
+		return [NSCursor IBeamCursor];
+	case PUGL_CURSOR_CROSSHAIR:
+		return [NSCursor crosshairCursor];
+	case PUGL_CURSOR_HAND:
+		return [NSCursor pointingHandCursor];
+	case PUGL_CURSOR_NO:
+		return [NSCursor operationNotAllowedCursor];
+	case PUGL_CURSOR_LEFT_RIGHT:
+		return [NSCursor resizeLeftRightCursor];
+	case PUGL_CURSOR_UP_DOWN:
+		return [NSCursor resizeUpDownCursor];
+	}
+
+	return NULL;
+}
+
+PuglStatus
+puglSetCursor(PuglView* view, PuglCursor cursor)
+{
+	PuglInternals* const impl = view->impl;
+	NSCursor* const      cur  = puglGetNsCursor(cursor);
+	if (!cur) {
+		return PUGL_FAILURE;
+	}
+
+	impl->cursor = cur;
+
+	if (impl->mouseTracked) {
+		[cur set];
+	}
+
+	return PUGL_SUCCESS;
+}
+
 PuglStatus
 puglSetClipboard(PuglView* const   view,
                  const char* const type,
diff --git a/pugl/detail/win.c b/pugl/detail/win.c
index 4b73c99..3f9f8f9 100644
--- a/pugl/detail/win.c
+++ b/pugl/detail/win.c
@@ -190,6 +190,8 @@ puglRealize(PuglView* view)
 		puglSetWindowTitle(view, view->title);
 	}
 
+	view->impl->cursor = LoadCursor(NULL, IDC_ARROW);
+
 	puglSetFrame(view, view->frame);
 	SetWindowLongPtr(impl->hwnd, GWLP_USERDATA, (LONG_PTR)view);
 
@@ -540,6 +542,11 @@ handleMessage(PuglView* view, UINT message, WPARAM wParam, LPARAM lParam)
 	}
 
 	switch (message) {
+	case WM_SETCURSOR:
+		if (LOWORD(lParam) == HTCLIENT) {
+			SetCursor(view->impl->cursor);
+		}
+		break;
 	case WM_SHOWWINDOW:
 		if (wParam) {
 			handleConfigure(view, &event);
@@ -1107,6 +1114,40 @@ puglWinStubLeave(PuglView* view, const PuglEventExpose* expose)
 	return PUGL_SUCCESS;
 }
 
+static const char* const cursor_ids[] = {
+    IDC_ARROW,  // ARROW
+    IDC_IBEAM,  // CARET
+    IDC_CROSS,  // CROSSHAIR
+    IDC_HAND,   // HAND
+    IDC_NO,     // NO
+    IDC_SIZEWE, // LEFT_RIGHT
+    IDC_SIZENS, // UP_DOWN
+};
+
+PuglStatus
+puglSetCursor(PuglView* view, PuglCursor cursor)
+{
+	PuglInternals* const impl  = view->impl;
+	const unsigned       index = (unsigned)cursor;
+	const unsigned       count = sizeof(cursor_ids) / sizeof(cursor_ids[0]);
+
+	if (index >= count) {
+		return PUGL_BAD_PARAMETER;
+	}
+
+	const HCURSOR cur = LoadCursor(NULL, cursor_ids[index]);
+	if (!cur) {
+		return PUGL_FAILURE;
+	}
+
+	impl->cursor = cur;
+	if (impl->mouseTracked) {
+		SetCursor(cur);
+	}
+
+	return PUGL_SUCCESS;
+}
+
 const PuglBackend*
 puglStubBackend(void)
 {
diff --git a/pugl/detail/win.h b/pugl/detail/win.h
index 087bbce..1b9b0c4 100644
--- a/pugl/detail/win.h
+++ b/pugl/detail/win.h
@@ -35,6 +35,7 @@ struct PuglInternalsImpl {
 	PuglWinPFD   pfd;
 	int          pfId;
 	HWND         hwnd;
+	HCURSOR      cursor;
 	HDC          hdc;
 	PuglSurface* surface;
 	DWORD        refreshRate;
diff --git a/pugl/detail/x11.c b/pugl/detail/x11.c
index da7b23d..2d74b68 100644
--- a/pugl/detail/x11.c
+++ b/pugl/detail/x11.c
@@ -41,6 +41,11 @@
 #	include <X11/extensions/syncconst.h>
 #endif
 
+#ifdef HAVE_XCURSOR
+#	include <X11/Xcursor/Xcursor.h>
+#	include <X11/cursorfont.h>
+#endif
+
 #include <sys/select.h>
 #include <sys/time.h>
 
@@ -152,7 +157,13 @@ puglGetNativeWorld(PuglWorld* world)
 PuglInternals*
 puglInitViewInternals(void)
 {
-	return (PuglInternals*)calloc(1, sizeof(PuglInternals));
+	PuglInternals* impl = (PuglInternals*)calloc(1, sizeof(PuglInternals));
+
+#ifdef HAVE_XCURSOR
+	impl->cursorShape = XC_arrow;
+#endif
+
+	return impl;
 }
 
 static PuglStatus
@@ -240,6 +251,25 @@ updateSizeHints(const PuglView* view)
 	return PUGL_SUCCESS;
 }
 
+#ifdef HAVE_XCURSOR
+static PuglStatus
+puglDefineCursorShape(PuglView* view, unsigned shape)
+{
+	PuglInternals* const impl    = view->impl;
+	PuglWorld* const     world   = view->world;
+	Display* const       display = world->impl->display;
+	const Cursor         cur     = XcursorShapeLoadCursor(display, shape);
+
+	if (cur) {
+		XDefineCursor(display, impl->win, cur);
+		XFreeCursor(display, cur);
+		return PUGL_SUCCESS;
+	}
+
+	return PUGL_FAILURE;
+}
+#endif
+
 PuglStatus
 puglRealize(PuglView* view)
 {
@@ -323,6 +353,10 @@ puglRealize(PuglView* view)
 		                     "XCreateID failed\n");
 	}
 
+#ifdef HAVE_XCURSOR
+	puglDefineCursorShape(view, impl->cursorShape);
+#endif
+
 	puglDispatchSimpleEvent(view, PUGL_CREATE);
 
 	return PUGL_SUCCESS;
@@ -1234,6 +1268,44 @@ puglSetClipboard(PuglView* const   view,
 	return PUGL_SUCCESS;
 }
 
+#ifdef HAVE_XCURSOR
+static const unsigned cursor_nums[] = {
+    XC_arrow,             // ARROW
+    XC_xterm,             // CARET
+    XC_crosshair,         // CROSSHAIR
+    XC_hand2,             // HAND
+    XC_pirate,            // NO
+    XC_sb_h_double_arrow, // LEFT_RIGHT
+    XC_sb_v_double_arrow, // UP_DOWN
+};
+#endif
+
+PuglStatus
+puglSetCursor(PuglView* view, PuglCursor cursor)
+{
+#ifdef HAVE_XCURSOR
+	PuglInternals* const impl  = view->impl;
+	const unsigned       index = (unsigned)cursor;
+	const unsigned       count = sizeof(cursor_nums) / sizeof(cursor_nums[0]);
+	if (index >= count) {
+		return PUGL_BAD_PARAMETER;
+	}
+
+	const unsigned shape = cursor_nums[index];
+	if (!impl->win || impl->cursorShape == shape) {
+		return PUGL_SUCCESS;
+	}
+
+	impl->cursorShape = cursor_nums[index];
+
+	return puglDefineCursorShape(view, impl->cursorShape);
+#else
+	(void)view;
+	(void)cursor;
+	return PUGL_FAILURE;
+#endif
+}
+
 const PuglBackend*
 puglStubBackend(void)
 {
diff --git a/pugl/detail/x11.h b/pugl/detail/x11.h
index aac8177..164a57e 100644
--- a/pugl/detail/x11.h
+++ b/pugl/detail/x11.h
@@ -64,6 +64,9 @@ struct PuglInternalsImpl {
 	int          screen;
 	XVisualInfo* vi;
 	Window       win;
+#ifdef HAVE_XCURSOR
+	unsigned     cursorShape;
+#endif
 	XIC          xic;
 	PuglSurface* surface;
 	PuglEvent    pendingConfigure;
diff --git a/pugl/pugl.h b/pugl/pugl.h
index b489407..3d80d6e 100644
--- a/pugl/pugl.h
+++ b/pugl/pugl.h
@@ -1124,6 +1124,22 @@ puglPostRedisplayRect(PuglView* view, PuglRect rect);
 */
 
 /**
+   A mouse cursor type.
+
+   This is a portable subset of mouse cursors that exist on X11, MacOS, and
+   Windows.
+*/
+typedef enum {
+	PUGL_CURSOR_ARROW,      ///< Default pointing arrow
+	PUGL_CURSOR_CARET,      ///< Caret (I-Beam) for text entry
+	PUGL_CURSOR_CROSSHAIR,  ///< Cross-hair
+	PUGL_CURSOR_HAND,       ///< Hand with a pointing finger
+	PUGL_CURSOR_NO,         ///< Operation not allowed
+	PUGL_CURSOR_LEFT_RIGHT, ///< Left/right arrow for horizontal resize
+	PUGL_CURSOR_UP_DOWN,    ///< Up/down arrow for vertical resize
+} PuglCursor;
+
+/**
    Grab the keyboard input focus.
 */
 PUGL_API PuglStatus
@@ -1167,6 +1183,16 @@ PUGL_API const void*
 puglGetClipboard(PuglView* view, const char** type, size_t* len);
 
 /**
+   Set the mouse cursor.
+
+   This changes the system cursor that is displayed when the pointer is inside
+   the view.  May fail if setting the cursor is not supported on this system,
+   for example if compiled on X11 without Xcursor support.
+ */
+PUGL_API PuglStatus
+puglSetCursor(PuglView* view, PuglCursor cursor);
+
+/**
    Request user attention.
 
    This hints to the system that the window or application requires attention
diff --git a/pugl/pugl.hpp b/pugl/pugl.hpp
index 2e18306..f1aef2f 100644
--- a/pugl/pugl.hpp
+++ b/pugl/pugl.hpp
@@ -357,6 +357,19 @@ static_assert(ViewHint(PUGL_IGNORE_KEY_REPEAT) == ViewHint::ignoreKeyRepeat,
 
 using ViewHintValue = PuglViewHintValue; ///< @copydoc PuglViewHintValue
 
+/// @copydoc PuglCursor
+enum class Cursor {
+	arrow,     ///< @copydoc PUGL_CURSOR_ARROW
+	caret,     ///< @copydoc PUGL_CURSOR_CARET
+	crosshair, ///< @copydoc PUGL_CURSOR_CROSSHAIR
+	hand,      ///< @copydoc PUGL_CURSOR_HAND
+	no,        ///< @copydoc PUGL_CURSOR_NO
+	leftRight, ///< @copydoc PUGL_CURSOR_LEFT_RIGHT
+	upDown,    ///< @copydoc PUGL_CURSOR_UP_DOWN
+};
+
+static_assert(Cursor(PUGL_CURSOR_UP_DOWN) == Cursor::upDown, "");
+
 /// @copydoc PuglView
 class View : public detail::Wrapper<PuglView, puglFreeView>
 {
@@ -514,6 +527,13 @@ public:
 		return static_cast<Status>(puglSetBackend(cobj(), backend));
 	}
 
+	/// @copydoc puglSetCursor
+	Status setCursor(const Cursor cursor)
+	{
+		return static_cast<Status>(
+		    puglSetCursor(cobj(), static_cast<PuglCursor>(cursor)));
+	}
+
 	/// @copydoc puglRequestAttention
 	Status requestAttention()
 	{