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eba9c15746
The patch adjust the code of the base, base-<kernel>, and os repository.
To adapt existing components to fix violations of the best practices
suggested by "Effective C++" as reported by the -Weffc++ compiler
argument. The changes follow the patterns outlined below:
* A class with virtual functions can no longer publicly inherit base
classed without a vtable. The inherited object may either be moved
to a member variable, or inherited privately. The latter would be
used for classes that inherit 'List::Element' or 'Avl_node'. In order
to enable the 'List' and 'Avl_tree' to access the meta data, the
'List' must become a friend.
* Instead of adding a virtual destructor to abstract base classes,
we inherit the new 'Interface' class, which contains a virtual
destructor. This way, single-line abstract base classes can stay
as compact as they are now. The 'Interface' utility resides in
base/include/util/interface.h.
* With the new warnings enabled, all member variables must be explicitly
initialized. Basic types may be initialized with '='. All other types
are initialized with braces '{ ... }' or as class initializers. If
basic types and non-basic types appear in a row, it is nice to only
use the brace syntax (also for basic types) and align the braces.
* If a class contains pointers as members, it must now also provide a
copy constructor and assignment operator. In the most cases, one
would make them private, effectively disallowing the objects to be
copied. Unfortunately, this warning cannot be fixed be inheriting
our existing 'Noncopyable' class (the compiler fails to detect that
the inheriting class cannot be copied and still gives the error).
For now, we have to manually add declarations for both the copy
constructor and assignment operator as private class members. Those
declarations should be prepended with a comment like this:
/*
* Noncopyable
*/
Thread(Thread const &);
Thread &operator = (Thread const &);
In the future, we should revisit these places and try to replace
the pointers with references. In the presence of at least one
reference member, the compiler would no longer implicitly generate
a copy constructor. So we could remove the manual declaration.
Issue #465
54 lines
1.3 KiB
C++
54 lines
1.3 KiB
C++
/*
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* \brief Graphics backend interface
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* \date 2013-12-30
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* \author Norman Feske
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*/
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/*
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* Copyright (C) 2013-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _INCLUDE__SCOUT__GRAPHICS_BACKEND_H_
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#define _INCLUDE__SCOUT__GRAPHICS_BACKEND_H_
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#include <scout/event.h>
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#include <scout/canvas.h>
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namespace Scout { struct Graphics_backend; }
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/*
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* We use two buffers, a foreground buffer that is displayed on screen and a
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* back buffer. While the foreground buffer must contain valid data all the
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* time, the back buffer can be used to prepare pixel data. For example,
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* drawing multiple pixel layers with alpha channel must be done in the back
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* buffer to avoid artifacts on the screen.
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*/
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struct Scout::Graphics_backend
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{
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virtual ~Graphics_backend() { }
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virtual Canvas_base &front() = 0;
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virtual Canvas_base &back() = 0;
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virtual void copy_back_to_front(Rect rect) = 0;
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virtual void swap_back_and_front() = 0;
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/*
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* XXX todo mode-change notification
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*/
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virtual void position(Point p) = 0;
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virtual void bring_to_front() = 0;
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virtual void view_area(Area area) = 0;
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};
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#endif /* _INCLUDE__SCOUT__GRAPHICS_BACKEND_H_ */
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