/* $Id: ttkTrack.c,v 1.4.2.1 2010/08/26 02:06:10 hobbs Exp $ * 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 events, * and remains "active" and "pressed" until the corresponding * event. * * TODO: Handle "chords" properly (e.g., ) */ #include #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); }