74 lines
2.4 KiB
C++
74 lines
2.4 KiB
C++
/*
|
|
* Copyright (C) 2014 David Robillard <d@drobilla.net>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <memory>
|
|
|
|
#include <gdkmm/cursor.h>
|
|
|
|
class EditingContext;
|
|
|
|
/**
|
|
A scoped handle for changing the editor mouse cursor.
|
|
|
|
This is a safe way to change the cursor that ensures it is only modified in
|
|
a strict stack-like fashion. Whenever this handle goes out of scope, the
|
|
cursor is restored to the previous one.
|
|
|
|
This is not quite entirely fool-proof, there is one case to be careful of:
|
|
if a cursor context handle exists, to change it, you must first reset that
|
|
handle (destroying the context) then set it. Assigning a new context to a
|
|
non-NULL handle will create the new context (pushing a cursor), then destroy
|
|
the old one, which would attempt to pop a non-top context which is an
|
|
error. To account for this, when replacing a possibly existing context, use
|
|
set() which will automatically do the right thing.
|
|
*/
|
|
class CursorContext
|
|
{
|
|
public:
|
|
/** A smart handle for a cursor change context. */
|
|
typedef std::shared_ptr<CursorContext> Handle;
|
|
|
|
~CursorContext();
|
|
|
|
/** Change the editor cursor and return a cursor context handle.
|
|
*
|
|
* When the returned handle goes out of scope, the cursor will be reset to
|
|
* the previous value.
|
|
*/
|
|
static Handle create(EditingContext&, Gdk::Cursor* cursor);
|
|
|
|
/** Change the editor cursor of an existing cursor context. */
|
|
void change(Gdk::Cursor* cursor);
|
|
|
|
/** Set a context handle to a new context.
|
|
*
|
|
* If the handle points to an existing context, it will first be reset
|
|
* before the new context is created.
|
|
*/
|
|
static void set(Handle* handle, EditingContext&, Gdk::Cursor* cursor);
|
|
|
|
private:
|
|
EditingContext& editing_context;
|
|
size_t _index;
|
|
|
|
CursorContext(EditingContext&, Gdk::Cursor* cursor);
|
|
};
|
|
|