diff options
Diffstat (limited to 'generic/ttk/ttkTrack.c')
| -rw-r--r-- | generic/ttk/ttkTrack.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/generic/ttk/ttkTrack.c b/generic/ttk/ttkTrack.c new file mode 100644 index 0000000..9cf8267 --- /dev/null +++ b/generic/ttk/ttkTrack.c @@ -0,0 +1,183 @@ +/* + * Copyright (c) 2004, Joe English + * + * TtkTrackElementState() -- helper routine for widgets + * like scrollbars in which individual elements may + * be active or pressed instead of the widget as a whole. + * + * Usage: + * TtkTrackElementState(&recordPtr->core); + * + * Registers an event handler on the widget that tracks pointer + * events and updates the state of the element under the + * mouse cursor. + * + * The "active" element is the one under the mouse cursor, + * and is normally set to the ACTIVE state unless another element + * is currently being pressed. + * + * The active element becomes "pressed" on <ButtonPress> events, + * and remains "active" and "pressed" until the corresponding + * <ButtonRelease> event. + * + * TODO: Handle "chords" properly (e.g., <B1-ButtonPress-2>) + */ + +#include <tk.h> +#include "ttkTheme.h" +#include "ttkWidget.h" + +typedef struct { + WidgetCore *corePtr; /* widget to track */ + Ttk_Layout tracking; /* current layout being tracked */ + Ttk_Element activeElement; /* element under the mouse cursor */ + Ttk_Element pressedElement; /* currently pressed element */ +} ElementStateTracker; + +/* + * ActivateElement(es, node) -- + * Make 'node' the active element if non-NULL. + * Deactivates the currently active element if different. + * + * The active element has TTK_STATE_ACTIVE set _unless_ + * another element is 'pressed' + */ +static void ActivateElement(ElementStateTracker *es, Ttk_Element element) +{ + if (es->activeElement == element) { + /* No change */ + return; + } + + if (!es->pressedElement) { + if (es->activeElement) { + /* Deactivate old element */ + Ttk_ChangeElementState(es->activeElement, 0,TTK_STATE_ACTIVE); + } + if (element) { + /* Activate new element */ + Ttk_ChangeElementState(element, TTK_STATE_ACTIVE,0); + } + TtkRedisplayWidget(es->corePtr); + } + + es->activeElement = element; +} + +/* ReleaseElement -- + * Releases the currently pressed element, if any. + */ +static void ReleaseElement(ElementStateTracker *es) +{ + if (!es->pressedElement) + return; + + Ttk_ChangeElementState( + es->pressedElement, 0,TTK_STATE_PRESSED|TTK_STATE_ACTIVE); + es->pressedElement = 0; + + /* Reactivate element under the mouse cursor: + */ + if (es->activeElement) + Ttk_ChangeElementState(es->activeElement, TTK_STATE_ACTIVE,0); + + TtkRedisplayWidget(es->corePtr); +} + +/* PressElement -- + * Presses the specified element. + */ +static void PressElement(ElementStateTracker *es, Ttk_Element element) +{ + if (es->pressedElement) { + ReleaseElement(es); + } + + if (element) { + Ttk_ChangeElementState( + element, TTK_STATE_PRESSED|TTK_STATE_ACTIVE, 0); + } + + es->pressedElement = element; + TtkRedisplayWidget(es->corePtr); +} + +/* ElementStateEventProc -- + * Event handler for tracking element states. + */ + +static const unsigned ElementStateMask = + ButtonPressMask + | ButtonReleaseMask + | PointerMotionMask + | LeaveWindowMask + | EnterWindowMask + | StructureNotifyMask + ; + +static void +ElementStateEventProc(ClientData clientData, XEvent *ev) +{ + ElementStateTracker *es = clientData; + Ttk_Layout layout = es->corePtr->layout; + Ttk_Element element; + + /* Guard against dangling pointers [#2431428] + */ + if (es->tracking != layout) { + es->pressedElement = es->activeElement = 0; + es->tracking = layout; + } + + switch (ev->type) + { + case MotionNotify : + element = Ttk_IdentifyElement( + layout, ev->xmotion.x, ev->xmotion.y); + ActivateElement(es, element); + break; + case LeaveNotify: + ActivateElement(es, 0); + if (ev->xcrossing.mode == NotifyGrab) + PressElement(es, 0); + break; + case EnterNotify: + element = Ttk_IdentifyElement( + layout, ev->xcrossing.x, ev->xcrossing.y); + ActivateElement(es, element); + break; + case ButtonPress: + element = Ttk_IdentifyElement( + layout, ev->xbutton.x, ev->xbutton.y); + if (element) + PressElement(es, element); + break; + case ButtonRelease: + ReleaseElement(es); + break; + case DestroyNotify: + /* Unregister this event handler and free client data. + */ + Tk_DeleteEventHandler(es->corePtr->tkwin, + ElementStateMask, ElementStateEventProc, es); + ckfree(clientData); + break; + } +} + +/* + * TtkTrackElementState -- + * Register an event handler to manage the 'pressed' + * and 'active' states of individual widget elements. + */ + +void TtkTrackElementState(WidgetCore *corePtr) +{ + ElementStateTracker *es = (ElementStateTracker*)ckalloc(sizeof(*es)); + es->corePtr = corePtr; + es->tracking = 0; + es->activeElement = es->pressedElement = 0; + Tk_CreateEventHandler(corePtr->tkwin, + ElementStateMask,ElementStateEventProc,es); +} + |