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/*
* Copyright © 2014 Canonical Ltd.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3,
* as published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Authored by: Robert Carr <robert.carr@canonical.com>
*/
#include "xcursor_loader.h"
#include "mir/graphics/cursor_image.h"
#include <boost/throw_exception.hpp>
#include <stdexcept>
#include <string.h>
#include <mir_toolkit/cursors.h>
// Unfortunately this can not be compiled as C++...so we can not namespace
// these symbols. In order to differentiate from internal symbols
// we refer to them via their _ prefixed version, i.e. _XcursorImage
extern "C"
{
#include "xcursor.h"
}
namespace me = mir::examples;
namespace mg = mir::graphics;
namespace mi = mir::input;
namespace geom = mir::geometry;
namespace
{
class XCursorImage : public mg::CursorImage
{
public:
XCursorImage(_XcursorImage *image, std::shared_ptr<_XcursorImages> const& save_resource)
: image(image),
save_resource(save_resource)
{
if (image->width != mi::default_cursor_size.width.as_uint32_t() ||
image->height != mi::default_cursor_size.height.as_uint32_t())
{
BOOST_THROW_EXCEPTION(
std::runtime_error("Somehow we got a cursor not of the default size (currently only 24x24 supported)"));
}
}
~XCursorImage()
{
}
void const* as_argb_8888() const override
{
return image->pixels;
}
geom::Size size() const override
{
return mi::default_cursor_size;
}
geom::Displacement hotspot() const override
{
return {image->xhot, image->yhot};
}
private:
_XcursorImage *image;
std::shared_ptr<_XcursorImages> const save_resource;
};
std::string const
xcursor_name_for_mir_cursor(std::string const& mir_cursor_name)
{
if (mir_cursor_name == mir_default_cursor_name)
{
return "arrow";
}
else if (mir_cursor_name == mir_arrow_cursor_name)
{
return "arrow";
}
else if (mir_cursor_name == mir_busy_cursor_name)
{
return "watch";
}
else if (mir_cursor_name == mir_caret_cursor_name)
{
return "xterm"; // Yep
}
else if (mir_cursor_name == mir_pointing_hand_cursor_name)
{
return "hand2";
}
else if (mir_cursor_name == mir_open_hand_cursor_name)
{
return "hand";
}
else if (mir_cursor_name == mir_closed_hand_cursor_name)
{
return "grabbing";
}
else if (mir_cursor_name == mir_horizontal_resize_cursor_name)
{
return "h_double_arrow";
}
else if (mir_cursor_name == mir_vertical_resize_cursor_name)
{
return "v_double_arrow";
}
else if (mir_cursor_name == mir_diagonal_resize_bottom_to_top_cursor_name)
{
return "top_right_corner";
}
else if (mir_cursor_name == mir_diagonal_resize_top_to_bottom_cursor_name)
{
return "bottom_right_corner";
}
else if (mir_cursor_name == mir_omnidirectional_resize_cursor_name)
{
return "fleur";
}
else if (mir_cursor_name == mir_vsplit_resize_cursor_name)
{
return "v_double_arrow";
}
else if (mir_cursor_name == mir_hsplit_resize_cursor_name)
{
return "h_double_arrow";
}
else if (mir_cursor_name == mir_crosshair_cursor_name)
{
return "crosshair";
}
else
{
return mir_cursor_name;
}
}
}
me::XCursorLoader::XCursorLoader()
{
load_cursor_theme("default");
}
me::XCursorLoader::XCursorLoader(std::string const& theme)
{
load_cursor_theme(theme);
}
// Each XcursorImages represents images for the different sizes of a given symbolic cursor.
void me::XCursorLoader::load_appropriately_sized_image(_XcursorImages *images)
{
// We would rather take this lock in load_cursor_theme but the Xcursor lib style
// makes it difficult to use our standard 'pass the lg around to _locked members' pattern
std::lock_guard<std::mutex> lg(guard);
// We have to save all the images as XCursor expects us to free them.
// This contains the actual image data though, so we need to ensure they stay alive
// with the lifetime of the mg::CursorImage instance which refers to them.
auto saved_xcursor_library_resource = std::shared_ptr<_XcursorImages>(images, [](_XcursorImages *images)
{
XcursorImagesDestroy(images);
});
_XcursorImage *image_of_correct_size = nullptr;
for (int i = 0; i < images->nimage; i++)
{
_XcursorImage *candidate = images->images[i];
if (candidate->width == mi::default_cursor_size.width.as_uint32_t() &&
candidate->height == mi::default_cursor_size.height.as_uint32_t())
{
image_of_correct_size = candidate;
break;
}
}
if (!image_of_correct_size)
return;
loaded_images[std::string(images->name)] = std::make_shared<XCursorImage>(image_of_correct_size, saved_xcursor_library_resource);
}
void me::XCursorLoader::load_cursor_theme(std::string const& theme_name)
{
// Cursors are named by their square dimension...called the nominal size in XCursor terminology, so we just look up by width.
// Later we verify the actual size.
xcursor_load_theme(theme_name.c_str(), mi::default_cursor_size.width.as_uint32_t(),
[](XcursorImages* images, void *this_ptr) -> void
{
// Can't use lambda capture as this lambda is thunked to a C function ptr
auto p = static_cast<me::XCursorLoader*>(this_ptr);
p->load_appropriately_sized_image(images);
}, this);
}
std::shared_ptr<mg::CursorImage> me::XCursorLoader::image(
std::string const& cursor_name,
geom::Size const& size)
{
auto xcursor_name = xcursor_name_for_mir_cursor(cursor_name);
if (size != mi::default_cursor_size)
BOOST_THROW_EXCEPTION(
std::logic_error("Only the default cursor size is currently supported (mi::default_cursor_size)"));
std::lock_guard<std::mutex> lg(guard);
auto it = loaded_images.find(xcursor_name);
if (it != loaded_images.end())
return it->second;
// Fall back
it = loaded_images.find("arrow");
if (it != loaded_images.end())
return it->second;
return nullptr;
}
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