Add puglSetCursor()

11 files changed, 397 insertions, 4 deletions

diff --git a/AUTHORS b/AUTHORS
index 1470491..18aadaf 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -8,4 +8,5 @@ Hanspeter Portner <dev@open-music-kontrollers.ch>
 Stefan Westerfeld <stefan@space.twc.de>
 Jordan Halase <jordan@halase.me>
 Oliver Schmidt <oliver@luced.de>
-Zoë Sparks <zoe@milky.flowers>
\ No newline at end of file
+Zoë Sparks <zoe@milky.flowers>
+Jean Pierre Cimalando <jp-dev@inbox.ru>
diff --git a/examples/pugl_cursor_demo.c b/examples/pugl_cursor_demo.c
new file mode 100644
index 0000000..244d22f
--- /dev/null
+++ b/examples/pugl_cursor_demo.c
@@ -0,0 +1,171 @@
+/*
+  Copyright 2012-2020 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/**
+   @file pugl_cursor_demo.c
+   @brief An example of changing the mouse cursor.
+*/
+
+#include "test/test_utils.h"
+
+#include "pugl/gl.h"
+#include "pugl/pugl.h"
+#include "pugl/pugl_gl.h"
+
+#include <stdbool.h>
+
+static const int N_CURSORS = 7;
+static const int N_ROWS    = 2;
+static const int N_COLS    = 4;
+
+typedef struct {
+	PuglTestOptions opts;
+	PuglWorld*      world;
+	bool            quit;
+} PuglTestApp;
+
+static void
+onConfigure(const double width, const double height)
+{
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LESS);
+	glClearColor(0.2f, 0.2f, 0.2f, 1.0f);
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glViewport(0, 0, (int)width, (int)height);
+}
+
+static void
+onExpose(void)
+{
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glColor3f(0.6f, 0.6f, 0.6f);
+
+	for (int row = 1; row < N_ROWS; ++row) {
+		const float y = (float)row * (2.0f / (float)N_ROWS) - 1.0f;
+		glBegin(GL_LINES);
+		glVertex2f(-1.0f, y);
+		glVertex2f(1.0f, y);
+		glEnd();
+	}
+
+	for (int col = 1; col < N_COLS; ++col) {
+		const float x = (float)col * (2.0f / (float)N_COLS) - 1.0f;
+		glBegin(GL_LINES);
+		glVertex2f(x, -1.0f);
+		glVertex2f(x, 1.0f);
+		glEnd();
+	}
+}
+
+static void
+onMotion(PuglView* view, double x, double y)
+{
+	const PuglRect frame = puglGetFrame(view);
+	int            row   = (int)(y * N_ROWS / frame.height);
+	int            col   = (int)(x * N_COLS / frame.width);
+
+	row = (row < 0) ? 0 : (row >= N_ROWS) ? (N_ROWS - 1) : row;
+	col = (col < 0) ? 0 : (col >= N_COLS) ? (N_COLS - 1) : col;
+
+	const PuglCursor cursor = (PuglCursor)((row * N_COLS + col) % N_CURSORS);
+	puglSetCursor(view, cursor);
+}
+
+static PuglStatus
+onEvent(PuglView* view, const PuglEvent* event)
+{
+	PuglTestApp* app = (PuglTestApp*)puglGetHandle(view);
+
+	printEvent(event, "Event: ", app->opts.verbose);
+
+	switch (event->type) {
+	case PUGL_CONFIGURE:
+		onConfigure(event->configure.width, event->configure.height);
+		break;
+	case PUGL_KEY_PRESS:
+		if (event->key.key == 'q' || event->key.key == PUGL_KEY_ESCAPE) {
+			app->quit = 1;
+		}
+		break;
+	case PUGL_MOTION:
+		onMotion(view, event->motion.x, event->motion.y);
+		break;
+	case PUGL_EXPOSE:
+		onExpose();
+		break;
+	case PUGL_CLOSE:
+		app->quit = 1;
+		break;
+	default:
+		break;
+	}
+
+	return PUGL_SUCCESS;
+}
+
+int
+main(int argc, char** argv)
+{
+	PuglTestApp app = {0};
+
+	app.opts = puglParseTestOptions(&argc, &argv);
+	if (app.opts.help) {
+		puglPrintTestUsage(argv[0], "");
+		return 1;
+	}
+
+	app.world = puglNewWorld(PUGL_PROGRAM, 0);
+
+	puglSetWorldHandle(app.world, &app);
+	puglSetClassName(app.world, "Pugl Test");
+
+	PuglView* view = puglNewView(app.world);
+
+	puglSetWindowTitle(view, "Pugl Window Demo");
+	puglSetDefaultSize(view, 512, 256);
+	puglSetMinSize(view, 128, 64);
+	puglSetBackend(view, puglGlBackend());
+
+	puglSetViewHint(view, PUGL_USE_DEBUG_CONTEXT, app.opts.errorChecking);
+	puglSetViewHint(view, PUGL_RESIZABLE, app.opts.resizable);
+	puglSetViewHint(view, PUGL_SAMPLES, app.opts.samples);
+	puglSetViewHint(view, PUGL_DOUBLE_BUFFER, app.opts.doubleBuffer);
+	puglSetViewHint(view, PUGL_SWAP_INTERVAL, app.opts.sync);
+	puglSetViewHint(view, PUGL_IGNORE_KEY_REPEAT, app.opts.ignoreKeyRepeat);
+	puglSetHandle(view, &app);
+	puglSetEventFunc(view, onEvent);
+
+	const PuglStatus st = puglRealize(view);
+	if (st) {
+		return logError("Failed to create window (%s)\n", puglStrerror(st));
+	}
+
+	puglShowWindow(view);
+
+	while (!app.quit) {
+		puglUpdate(app.world, -1.0);
+	}
+
+	puglFreeView(view);
+	puglFreeWorld(app.world);
+
+	return 0;
+}
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()
 	{
diff --git a/wscript b/wscript
index da520e0..ce10d58 100644
--- a/wscript
+++ b/wscript
@@ -125,6 +125,11 @@ def configure(conf):
                          msg='Checking for function XSyncQueryExtension'):
             conf.define('HAVE_XSYNC', 1)
 
+        if conf.check_cc(lib='Xcursor',
+                         uselib_store='XCURSOR',
+                         mandatory=False):
+            conf.define('HAVE_XCURSOR', 1)
+
         if not Options.options.no_gl:
             glx_fragment = """#include <GL/glx.h>
                 int main(void) { glXSwapBuffers(0, 0); return 0; }"""
@@ -309,7 +314,7 @@ def build(bld):
     else:
         platform = 'x11'
         build_platform('x11',
-                       uselib=['M', 'X11', 'XSYNC'],
+                       uselib=['M', 'X11', 'XSYNC', 'XCURSOR'],
                        source=lib_source + ['pugl/detail/x11.c'])
 
         if bld.env.HAVE_GL:
@@ -366,6 +371,8 @@ def build(bld):
                           platform, 'gl', uselib=['GL', 'M'])
             build_example('pugl_window_demo', ['examples/pugl_window_demo.c'],
                           platform, 'gl', uselib=['GL', 'M'])
+            build_example('pugl_cursor_demo', ['examples/pugl_cursor_demo.c'],
+                          platform, 'gl', uselib=['GL', 'M'])
             build_example('pugl_print_events',
                           ['examples/pugl_print_events.c'],
                           platform, 'stub')