mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-06 09:05:45 +00:00
133 lines
3.4 KiB
C++
133 lines
3.4 KiB
C++
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef _MOZILLA_GFX_BORROWED_CONTEXT_H
|
|
#define _MOZILLA_GFX_BORROWED_CONTEXT_H
|
|
|
|
#include "2D.h"
|
|
|
|
struct _cairo;
|
|
typedef struct _cairo cairo_t;
|
|
|
|
namespace mozilla {
|
|
|
|
namespace gfx {
|
|
|
|
/* This is a helper class that let's you borrow a cairo_t from a
|
|
* DrawTargetCairo. This is used for drawing themed widgets.
|
|
*
|
|
* Callers should check the cr member after constructing the object
|
|
* to see if it succeeded. The DrawTarget should not be used while
|
|
* the context is borrowed. */
|
|
class BorrowedCairoContext
|
|
{
|
|
public:
|
|
BorrowedCairoContext()
|
|
: mCairo(nullptr)
|
|
, mDT(nullptr)
|
|
{ }
|
|
|
|
BorrowedCairoContext(DrawTarget *aDT)
|
|
: mDT(aDT)
|
|
{
|
|
mCairo = BorrowCairoContextFromDrawTarget(aDT);
|
|
}
|
|
|
|
// We can optionally Init after construction in
|
|
// case we don't know what the DT will be at construction
|
|
// time.
|
|
cairo_t *Init(DrawTarget *aDT)
|
|
{
|
|
MOZ_ASSERT(!mDT, "Can't initialize twice!");
|
|
mDT = aDT;
|
|
return mCairo = BorrowCairoContextFromDrawTarget(aDT);
|
|
}
|
|
|
|
// The caller needs to call Finish if cr is non-null when
|
|
// they are done with the context. This is currently explicit
|
|
// instead of happening implicitly in the destructor to make
|
|
// what's happening in the caller more clear. It also
|
|
// let's you resume using the DrawTarget in the same scope.
|
|
void Finish()
|
|
{
|
|
if (mCairo) {
|
|
ReturnCairoContextToDrawTarget(mDT, mCairo);
|
|
mCairo = nullptr;
|
|
}
|
|
}
|
|
|
|
~BorrowedCairoContext() {
|
|
MOZ_ASSERT(!mCairo);
|
|
}
|
|
|
|
cairo_t *mCairo;
|
|
private:
|
|
static cairo_t* BorrowCairoContextFromDrawTarget(DrawTarget *aDT);
|
|
static void ReturnCairoContextToDrawTarget(DrawTarget *aDT, cairo_t *aCairo);
|
|
DrawTarget *mDT;
|
|
};
|
|
|
|
#ifdef XP_MACOSX
|
|
/* This is a helper class that let's you borrow a CGContextRef from a
|
|
* DrawTargetCG. This is used for drawing themed widgets.
|
|
*
|
|
* Callers should check the cg member after constructing the object
|
|
* to see if it succeeded. The DrawTarget should not be used while
|
|
* the context is borrowed. */
|
|
class BorrowedCGContext
|
|
{
|
|
public:
|
|
BorrowedCGContext()
|
|
: cg(nullptr)
|
|
, mDT(nullptr)
|
|
{ }
|
|
|
|
BorrowedCGContext(DrawTarget *aDT)
|
|
: mDT(aDT)
|
|
{
|
|
cg = BorrowCGContextFromDrawTarget(aDT);
|
|
}
|
|
|
|
// We can optionally Init after construction in
|
|
// case we don't know what the DT will be at construction
|
|
// time.
|
|
CGContextRef Init(DrawTarget *aDT)
|
|
{
|
|
MOZ_ASSERT(!mDT, "Can't initialize twice!");
|
|
mDT = aDT;
|
|
cg = BorrowCGContextFromDrawTarget(aDT);
|
|
return cg;
|
|
}
|
|
|
|
// The caller needs to call Finish if cg is non-null when
|
|
// they are done with the context. This is currently explicit
|
|
// instead of happening implicitly in the destructor to make
|
|
// what's happening in the caller more clear. It also
|
|
// let's you resume using the DrawTarget in the same scope.
|
|
void Finish()
|
|
{
|
|
if (cg) {
|
|
ReturnCGContextToDrawTarget(mDT, cg);
|
|
cg = nullptr;
|
|
}
|
|
}
|
|
|
|
~BorrowedCGContext() {
|
|
MOZ_ASSERT(!cg);
|
|
}
|
|
|
|
CGContextRef cg;
|
|
private:
|
|
static CGContextRef BorrowCGContextFromDrawTarget(DrawTarget *aDT);
|
|
static void ReturnCGContextToDrawTarget(DrawTarget *aDT, CGContextRef cg);
|
|
DrawTarget *mDT;
|
|
};
|
|
#endif
|
|
|
|
}
|
|
}
|
|
|
|
#endif // _MOZILLA_GFX_BORROWED_CONTEXT_H
|