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Changed drag area API to a hit-testing API.

There were several good arguments for this: it's how Windows works with
 WM_NCHITTEST, SDL doesn't need to manage a list of rects, it allows more
 control over the regions (how do you use rects to cleanly surround a circular
 button?), the callback can be more optimized than a iterating a list of
 rects, and you don't have to send an updated list of rects whenever the
 window resizes or layout changes.
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icculus committed May 28, 2014
1 parent 7a4ddcd commit 98c03f391d2dcd91acb6c37bb072920bd256741d
@@ -55,7 +55,6 @@ test/loopwave
test/testatomic
test/testaudioinfo
test/testautomation
test/testdragareas
test/testdraw2
test/testerror
test/testfile
@@ -64,6 +63,7 @@ test/testgesture
test/testgl2
test/testgles
test/testhaptic
test/testhittesting
test/testiconv
test/testime
test/testintersections
@@ -791,43 +791,51 @@ extern DECLSPEC int SDLCALL SDL_GetWindowGammaRamp(SDL_Window * window,
Uint16 * green,
Uint16 * blue);

typedef enum
{
SDL_HITTEST_NORMAL, /**< Region is normal. No special properties. */
SDL_HITTEST_DRAGGABLE, /**< Region can drag entire window. */
/* !!! FIXME: resize enums here. */
} SDL_HitTestResult;

typedef SDL_HitTestResult (SDLCALL *SDL_HitTest)(SDL_Window *win,
const SDL_Point *area,
void *data);

/**
* \brief Define regions of a window that can be used to drag it.
* \brief Provide a callback that decides if a window region has special properties.
*
* Normally windows are dragged by decorations provided by the system
* window manager (usually, a title bar), but for some apps, it makes sense
* to drag them from somewhere else inside the window itself; for example,
* one might have a borderless window that wants to be draggable from any
* part, or simulate its own title bar, etc.
* Normally windows are dragged and resized by decorations provided by the
* system window manager (a title bar, borders, etc), but for some apps, it
* makes sense to drag them from somewhere else inside the window itself; for
* example, one might have a borderless window that wants to be draggable
* from any part, or simulate its own title bar, etc.
*
* This method designates pieces of a given window as "drag areas," which
* will move the window when the user drags with his mouse, as if she had
* used the titlebar.
*
* You may specify multiple drag areas, disconnected or overlapping. This
* function accepts an array of rectangles. Each call to this function will
* replace any previously-defined drag areas. To disable drag areas on a
* window, call this function with a NULL array of zero elements.
*
* Drag areas do not automatically resize. If your window changes dimensions
* you should plan to re-call this function with new drag areas if
* appropriate.
* This function lets the app provide a callback that designates pieces of
* a given window as special. This callback is run during event processing
* if we need to tell the OS to treat a region of the window specially; the
* use of this callback is known as "hit testing."
*
* Mouse input may not be delivered to your application if it is within
* a drag area; the OS will often apply that input to moving the window and
* not deliver it to the application.
* a special area; the OS will often apply that input to moving the window or
* resizing the window and not deliver it to the application.
*
* Specifying NULL for a callback disables hit-testing. Hit-testing is
* disabled by default.
*
* Platforms that don't support this functionality will return -1
* unconditionally, even if you're attempting to disable drag areas.
* unconditionally, even if you're attempting to disable hit-testing.
*
* Your callback may fire at any time.
*
* \param window The window to set drag areas on.
* \param areas An array of SDL_Rects containing num_areas elements.
* \param num_areas The number of elements in the areas parameter.
* \param window The window to set hit-testing on.
* \param callback The callback to call when doing a hit-test.
* \param callback_data An app-defined void pointer passed to the callback.
* \return 0 on success, -1 on error (including unsupported).
*/
extern DECLSPEC int SDLCALL SDL_SetWindowDragAreas(SDL_Window * window,
const SDL_Rect *areas,
int num_areas);
extern DECLSPEC int SDLCALL SDL_SetWindowHitTest(SDL_Window * window,
SDL_HitTest callback,
void *callback_data);

/**
* \brief Destroy a window.
@@ -580,4 +580,4 @@
#define SDL_WinRTGetFSPathUTF8 SDL_WinRTGetFSPathUTF8_REAL
#define SDL_WinRTRunApp SDL_WinRTRunApp_REAL
#define SDL_CaptureMouse SDL_CaptureMouse_REAL
#define SDL_SetWindowDragAreas SDL_SetWindowDragAreas_REAL
#define SDL_SetWindowHitTest SDL_SetWindowHitTest_REAL
@@ -613,4 +613,4 @@ SDL_DYNAPI_PROC(const char*,SDL_WinRTGetFSPathUTF8,(SDL_WinRT_Path a),(a),return
SDL_DYNAPI_PROC(int,SDL_WinRTRunApp,(int a, char **b, void *c),(a,b,c),return)
#endif
SDL_DYNAPI_PROC(int,SDL_CaptureMouse,(SDL_bool a),(a),return)
SDL_DYNAPI_PROC(int,SDL_SetWindowDragAreas,(SDL_Window *a, const SDL_Rect *b, int c),(a,b,c),return)
SDL_DYNAPI_PROC(int,SDL_SetWindowHitTest,(SDL_Window *a, SDL_HitTest b, void *c),(a,b,c),return)
@@ -97,8 +97,8 @@ struct SDL_Window

SDL_WindowShaper *shaper;

int num_drag_areas;
SDL_Rect *drag_areas;
SDL_HitTest hit_test;
void *hit_test_data;

SDL_WindowUserData *data;

@@ -264,8 +264,8 @@ struct SDL_VideoDevice
/* MessageBox */
int (*ShowMessageBox) (_THIS, const SDL_MessageBoxData *messageboxdata, int *buttonid);

/* Drag areas. Note that (areas) and (num_areas) are also copied to the SDL_Window for you after this call. */
int (*SetWindowDragAreas)(SDL_Window * window, const SDL_Rect *areas, int num_areas);
/* Hit-testing */
int (*SetWindowHitTest)(SDL_Window * window, SDL_bool enabled);

/* * * */
/* Data common to all drivers */
@@ -1411,8 +1411,8 @@ SDL_RecreateWindow(SDL_Window * window, Uint32 flags)
SDL_FreeSurface(icon);
}

if (window->num_drag_areas > 0) {
_this->SetWindowDragAreas(window, window->drag_areas, window->num_drag_areas);
if (window->hit_test > 0) {
_this->SetWindowHitTest(window, SDL_TRUE);
}

SDL_FinishWindowCreation(window, flags);
@@ -2310,8 +2310,6 @@ SDL_DestroyWindow(SDL_Window * window)
_this->windows = window->next;
}

SDL_free(window->drag_areas);

SDL_free(window);
}

@@ -3388,33 +3386,20 @@ SDL_ShouldAllowTopmost(void)
}

int
SDL_SetWindowDragAreas(SDL_Window * window, const SDL_Rect *_areas, int num_areas)
SDL_SetWindowHitTest(SDL_Window * window, SDL_HitTest callback, void *userdata)
{
SDL_Rect *areas = NULL;

CHECK_WINDOW_MAGIC(window, -1);

if (!_this->SetWindowDragAreas) {
if (!_this->SetWindowHitTest) {
return SDL_Unsupported();
}

if (num_areas > 0) {
const size_t len = sizeof (SDL_Rect) * num_areas;
areas = (SDL_Rect *) SDL_malloc(len);
if (!areas) {
return SDL_OutOfMemory();
}
SDL_memcpy(areas, _areas, len);
}

if (_this->SetWindowDragAreas(window, areas, num_areas) == -1) {
SDL_free(areas);
} else if (_this->SetWindowHitTest(window, callback != NULL) == -1) {
return -1;
}

SDL_free(window->drag_areas);
window->drag_areas = areas;
window->num_drag_areas = num_areas;
window->hit_test = callback;
window->hit_test_data = userdata;

return 0;
}

/* vi: set ts=4 sw=4 expandtab: */
@@ -108,7 +108,7 @@
device->SetWindowGrab = Cocoa_SetWindowGrab;
device->DestroyWindow = Cocoa_DestroyWindow;
device->GetWindowWMInfo = Cocoa_GetWindowWMInfo;
device->SetWindowDragAreas = Cocoa_SetWindowDragAreas;
device->SetWindowHitTest = Cocoa_SetWindowHitTest;

device->shape_driver.CreateShaper = Cocoa_CreateShaper;
device->shape_driver.SetWindowShape = Cocoa_SetWindowShape;
@@ -77,7 +77,7 @@ typedef enum
-(NSApplicationPresentationOptions)window:(NSWindow *)window willUseFullScreenPresentationOptions:(NSApplicationPresentationOptions)proposedOptions;

/* See if event is in a drag area, toggle on window dragging. */
-(BOOL) processDragArea:(NSEvent *)theEvent;
-(BOOL) processHitTest:(NSEvent *)theEvent;

/* Window event handling */
-(void) mouseDown:(NSEvent *) theEvent;
@@ -119,7 +119,6 @@ struct SDL_WindowData
SDL_bool inWindowMove;
Cocoa_WindowListener *listener;
struct SDL_VideoData *videodata;
NSView *dragarea;
};

extern int Cocoa_CreateWindow(_THIS, SDL_Window * window);
@@ -144,7 +143,7 @@ extern int Cocoa_GetWindowGammaRamp(_THIS, SDL_Window * window, Uint16 * ramp);
extern void Cocoa_SetWindowGrab(_THIS, SDL_Window * window, SDL_bool grabbed);
extern void Cocoa_DestroyWindow(_THIS, SDL_Window * window);
extern SDL_bool Cocoa_GetWindowWMInfo(_THIS, SDL_Window * window, struct SDL_SysWMinfo *info);
extern int Cocoa_SetWindowDragAreas(SDL_Window *window, const SDL_Rect *areas, int num_areas);
extern int Cocoa_SetWindowHitTest(SDL_Window *window, SDL_bool enabled);

#endif /* _SDL_cocoawindow_h */

@@ -657,26 +657,20 @@ - (void)doCommandBySelector:(SEL)aSelector
/*NSLog(@"doCommandBySelector: %@\n", NSStringFromSelector(aSelector));*/
}

- (BOOL)processDragArea:(NSEvent *)theEvent
- (BOOL)processHitTest:(NSEvent *)theEvent
{
const int num_areas = _data->window->num_drag_areas;

SDL_assert(isDragAreaRunning == [_data->nswindow isMovableByWindowBackground]);
SDL_assert((num_areas > 0) || !isDragAreaRunning);

if (num_areas > 0) { /* if no drag areas, skip this. */
int i;
if (_data->window->hit_test) { /* if no hit-test, skip this. */
const NSPoint location = [theEvent locationInWindow];
const SDL_Point point = { (int) location.x, _data->window->h - (((int) location.y)-1) };
const SDL_Rect *areas = _data->window->drag_areas;
for (i = 0; i < num_areas; i++) {
if (SDL_PointInRect(&point, &areas[i])) {
if (!isDragAreaRunning) {
isDragAreaRunning = YES;
[_data->nswindow setMovableByWindowBackground:YES];
}
return YES; /* started a new drag! */
const SDL_HitTestResult rc = _data->window->hit_test(_data->window, &point, _data->window->hit_test_data);
if (rc == SDL_HITTEST_DRAGGABLE) {
if (!isDragAreaRunning) {
isDragAreaRunning = YES;
[_data->nswindow setMovableByWindowBackground:YES];
}
return YES; /* dragging! */
}
}

@@ -686,14 +680,14 @@ - (BOOL)processDragArea:(NSEvent *)theEvent
return YES; /* was dragging, drop event. */
}

return NO; /* not a drag area, carry on. */
return NO; /* not a special area, carry on. */
}

- (void)mouseDown:(NSEvent *)theEvent
{
int button;

if ([self processDragArea:theEvent]) {
if ([self processHitTest:theEvent]) {
return; /* dragging, drop event. */
}

@@ -735,7 +729,7 @@ - (void)mouseUp:(NSEvent *)theEvent
{
int button;

if ([self processDragArea:theEvent]) {
if ([self processHitTest:theEvent]) {
return; /* stopped dragging, drop event. */
}

@@ -778,7 +772,7 @@ - (void)mouseMoved:(NSEvent *)theEvent
NSPoint point;
int x, y;

if ([self processDragArea:theEvent]) {
if ([self processHitTest:theEvent]) {
return; /* dragging, drop event. */
}

@@ -1599,7 +1593,7 @@ - (void)resetCursorRects
}

int
Cocoa_SetWindowDragAreas(SDL_Window * window, const SDL_Rect *areas, int num_areas)
Cocoa_SetWindowHitTest(SDL_Window * window, SDL_bool enabled)
{
return 0; /* just succeed, the real work is done elsewhere. */
}
@@ -303,21 +303,16 @@ InitiateWindowMove(_THIS, const SDL_WindowData *data, const SDL_Point *point)
}

static SDL_bool
ProcessDragArea(_THIS, const SDL_WindowData *data, const XEvent *xev)
ProcessHitTest(_THIS, const SDL_WindowData *data, const XEvent *xev)
{
const SDL_Window *window = data->window;
const int num_areas = window->num_drag_areas;
SDL_Window *window = data->window;

if (num_areas > 0) {
if (window->hit_test) {
const SDL_Point point = { xev->xbutton.x, xev->xbutton.y };
const SDL_Rect *areas = window->drag_areas;
int i;

for (i = 0; i < num_areas; i++) {
if (SDL_PointInRect(&point, &areas[i])) {
InitiateWindowMove(_this, data, &point);
return SDL_TRUE; /* dragging, drop this event. */
}
const SDL_HitTestResult rc = window->hit_test(window, &point, window->hit_test_data);
if (rc == SDL_HITTEST_DRAGGABLE) {
InitiateWindowMove(_this, data, &point);
return SDL_TRUE; /* dragging, drop this event. */
}
}

@@ -762,7 +757,7 @@ X11_DispatchEvent(_THIS)
SDL_SendMouseWheel(data->window, 0, 0, ticks);
} else {
if(xevent.xbutton.button == Button1) {
if (ProcessDragArea(_this, data, &xevent)) {
if (ProcessHitTest(_this, data, &xevent)) {
break; /* don't pass this event on to app. */
}
}
@@ -457,7 +457,7 @@ X11_CreateDevice(int devindex)
device->UpdateWindowFramebuffer = X11_UpdateWindowFramebuffer;
device->DestroyWindowFramebuffer = X11_DestroyWindowFramebuffer;
device->GetWindowWMInfo = X11_GetWindowWMInfo;
device->SetWindowDragAreas = X11_SetWindowDragAreas;
device->SetWindowHitTest = X11_SetWindowHitTest;

device->shape_driver.CreateShaper = X11_CreateShaper;
device->shape_driver.SetWindowShape = X11_SetWindowShape;
@@ -1445,9 +1445,9 @@ X11_GetWindowWMInfo(_THIS, SDL_Window * window, SDL_SysWMinfo * info)
}

int
X11_SetWindowDragAreas(SDL_Window *window, const SDL_Rect *areas, int num_areas)
X11_SetWindowHitTest(SDL_Window *window, SDL_bool enabled)
{
return 0; // nothing to do, will be handled in event handler
return 0; /* just succeed, the real work is done elsewhere. */
}

#endif /* SDL_VIDEO_DRIVER_X11 */
@@ -93,7 +93,7 @@ extern void X11_SetWindowGrab(_THIS, SDL_Window * window, SDL_bool grabbed);
extern void X11_DestroyWindow(_THIS, SDL_Window * window);
extern SDL_bool X11_GetWindowWMInfo(_THIS, SDL_Window * window,
struct SDL_SysWMinfo *info);
extern int X11_SetWindowDragAreas(SDL_Window *window, const SDL_Rect *areas, int num_areas);
extern int X11_SetWindowHitTest(SDL_Window *window, SDL_bool enabled);

#endif /* _SDL_x11window_h */

@@ -12,7 +12,6 @@ TARGETS = \
loopwave$(EXE) \
testaudioinfo$(EXE) \
testautomation$(EXE) \
testdragareas$(EXE) \
testdraw2$(EXE) \
testdrawchessboard$(EXE) \
testdropfile$(EXE) \
@@ -24,6 +23,7 @@ TARGETS = \
testgles$(EXE) \
testgles2$(EXE) \
testhaptic$(EXE) \
testhittesting$(EXE) \
testrumble$(EXE) \
testhotplug$(EXE) \
testthread$(EXE) \
@@ -109,7 +109,7 @@ testintersections$(EXE): $(srcdir)/testintersections.c
testrelative$(EXE): $(srcdir)/testrelative.c
$(CC) -o $@ $^ $(CFLAGS) $(LIBS)

testdragareas$(EXE): $(srcdir)/testdragareas.c
testhittesting$(EXE): $(srcdir)/testhittesting.c
$(CC) -o $@ $^ $(CFLAGS) $(LIBS)

testdraw2$(EXE): $(srcdir)/testdraw2.c

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