Method ApplyEventStyles

source/script_gui.cpp:2474–2547

void GuiType::ApplyEventStyles(GuiControlType *aControl, UINT aEvent, bool aAdded)
{
	int style_type;
	DWORD style_bit;
	HWND hwnd;
	if (aControl)
	{
		// These styles are only added automatically, not removed, for a few reasons:
		//  1) Reduces code size (by 224 bytes on x86 vs. just 64 bytes for this section).
		//     Note that it's necessary to check for handlers for every event in the group
		//     before removing the style.
		//  2) The script may have applied the style manually, in which case it should not
		//     be removed automatically (but we have no way to know).
		//  3) It's probably rare to remove a handler for one of these events.
		if (!aAdded)
			return;
		GuiControlType &control = *aControl;
		// This approach appears to produce the same code size as just checking for the
		// events which don't need the style; i.e. GUI_EVENT_CONTEXTMENU and (for Buttons)
		// GUI_EVENT_CLICK:
		static char sStaticNotify[] = {GUI_EVENT_CLICK, GUI_EVENT_DBLCLK, NULL};
		static char sButtonNotify[] = {GUI_EVENT_DBLCLK, GUI_EVENT_FOCUS, GUI_EVENT_LOSEFOCUS, NULL};
		char *event_group;
		switch (control.type)
		{
		case GUI_CONTROL_TEXT:
		case GUI_CONTROL_PIC:
			// Apply the SS_NOTIFY style *only* if the control actually has an associated action.
			// This is because otherwise the control would steal all clicks for any other controls
			// drawn on top of it (e.g. a picture control with some edit fields drawn on top of it).
			// See comments in the creation of GUI_CONTROL_PIC for more info:
			style_bit = SS_NOTIFY;
			event_group = sStaticNotify;
			break;
		
		case GUI_CONTROL_BUTTON:
		case GUI_CONTROL_CHECKBOX:
		case GUI_CONTROL_RADIO:
			style_bit = BS_NOTIFY;
			event_group = sButtonNotify;
			break;
		
		default:
			return;
		}
		if (!strchr(event_group, aEvent))
			return;
		style_type = GWL_STYLE;
		hwnd = control.hwnd;
	}
	else // aControl == NULL
	{
		if (aEvent == GUI_EVENT_DROPFILES)
		{
			// Apply the WS_EX_ACCEPTFILES style to ensure the window can accept dropped files.
			// Remove the style to ensure the mouse cursor correctly changes to show that the
			// window no longer accepts dropped files.
			style_type = GWL_EXSTYLE;