gecko-dev/gfx/src/nsDeviceContext.cpp

684 строки
20 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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/. */
#include "nsDeviceContext.h"
#include <algorithm> // for max
#include "gfxASurface.h" // for gfxASurface, etc
#include "gfxContext.h"
#include "gfxFont.h" // for gfxFontGroup
#include "gfxImageSurface.h" // for gfxImageSurface
#include "gfxPoint.h" // for gfxSize
#include "mozilla/Attributes.h" // for final
#include "mozilla/gfx/PathHelpers.h"
#include "mozilla/gfx/PrintTarget.h"
#include "mozilla/Preferences.h" // for Preferences
#include "mozilla/Services.h" // for GetObserverService
#include "mozilla/mozalloc.h" // for operator new
#include "nsCRT.h" // for nsCRT
#include "nsDebug.h" // for NS_NOTREACHED, NS_ASSERTION, etc
#include "nsFont.h" // for nsFont
#include "nsFontMetrics.h" // for nsFontMetrics
#include "nsIAtom.h" // for nsIAtom, NS_Atomize
#include "nsID.h"
#include "nsIDeviceContextSpec.h" // for nsIDeviceContextSpec
#include "nsILanguageAtomService.h" // for nsILanguageAtomService, etc
#include "nsIObserver.h" // for nsIObserver, etc
#include "nsIObserverService.h" // for nsIObserverService
#include "nsIScreen.h" // for nsIScreen
#include "nsIScreenManager.h" // for nsIScreenManager
#include "nsISupportsImpl.h" // for MOZ_COUNT_CTOR, etc
#include "nsISupportsUtils.h" // for NS_ADDREF, NS_RELEASE
#include "nsIWidget.h" // for nsIWidget, NS_NATIVE_WINDOW
#include "nsRect.h" // for nsRect
#include "nsServiceManagerUtils.h" // for do_GetService
#include "nsString.h" // for nsDependentString
#include "nsTArray.h" // for nsTArray, nsTArray_Impl
#include "nsThreadUtils.h" // for NS_IsMainThread
#include "mozilla/gfx/Logging.h"
using namespace mozilla;
using namespace mozilla::gfx;
using mozilla::services::GetObserverService;
class nsFontCache final : public nsIObserver
{
public:
nsFontCache() { MOZ_COUNT_CTOR(nsFontCache); }
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
void Init(nsDeviceContext* aContext);
void Destroy();
already_AddRefed<nsFontMetrics> GetMetricsFor(
const nsFont& aFont, const nsFontMetrics::Params& aParams);
void FontMetricsDeleted(const nsFontMetrics* aFontMetrics);
void Compact();
void Flush();
protected:
~nsFontCache() { MOZ_COUNT_DTOR(nsFontCache); }
nsDeviceContext* mContext; // owner
nsCOMPtr<nsIAtom> mLocaleLanguage;
nsTArray<nsFontMetrics*> mFontMetrics;
};
NS_IMPL_ISUPPORTS(nsFontCache, nsIObserver)
// The Init and Destroy methods are necessary because it's not
// safe to call AddObserver from a constructor or RemoveObserver
// from a destructor. That should be fixed.
void
nsFontCache::Init(nsDeviceContext* aContext)
{
mContext = aContext;
// register as a memory-pressure observer to free font resources
// in low-memory situations.
nsCOMPtr<nsIObserverService> obs = GetObserverService();
if (obs)
obs->AddObserver(this, "memory-pressure", false);
nsCOMPtr<nsILanguageAtomService> langService;
langService = do_GetService(NS_LANGUAGEATOMSERVICE_CONTRACTID);
if (langService) {
mLocaleLanguage = langService->GetLocaleLanguage();
}
if (!mLocaleLanguage) {
mLocaleLanguage = NS_Atomize("x-western");
}
}
void
nsFontCache::Destroy()
{
nsCOMPtr<nsIObserverService> obs = GetObserverService();
if (obs)
obs->RemoveObserver(this, "memory-pressure");
Flush();
}
NS_IMETHODIMP
nsFontCache::Observe(nsISupports*, const char* aTopic, const char16_t*)
{
if (!nsCRT::strcmp(aTopic, "memory-pressure"))
Compact();
return NS_OK;
}
already_AddRefed<nsFontMetrics>
nsFontCache::GetMetricsFor(const nsFont& aFont,
const nsFontMetrics::Params& aParams)
{
nsIAtom* language = aParams.language ? aParams.language
: mLocaleLanguage.get();
// First check our cache
// start from the end, which is where we put the most-recent-used element
int32_t n = mFontMetrics.Length() - 1;
for (int32_t i = n; i >= 0; --i) {
nsFontMetrics* fm = mFontMetrics[i];
if (fm->Font().Equals(aFont) &&
fm->GetUserFontSet() == aParams.userFontSet &&
fm->Language() == language &&
fm->Orientation() == aParams.orientation) {
if (i != n) {
// promote it to the end of the cache
mFontMetrics.RemoveElementAt(i);
mFontMetrics.AppendElement(fm);
}
fm->GetThebesFontGroup()->UpdateUserFonts();
return do_AddRef(fm);
}
}
// It's not in the cache. Get font metrics and then cache them.
nsFontMetrics::Params params = aParams;
params.language = language;
RefPtr<nsFontMetrics> fm = new nsFontMetrics(aFont, params, mContext);
// the mFontMetrics list has the "head" at the end, because append
// is cheaper than insert
mFontMetrics.AppendElement(do_AddRef(fm.get()).take());
return fm.forget();
}
void
nsFontCache::FontMetricsDeleted(const nsFontMetrics* aFontMetrics)
{
mFontMetrics.RemoveElement(aFontMetrics);
}
void
nsFontCache::Compact()
{
// Need to loop backward because the running element can be removed on
// the way
for (int32_t i = mFontMetrics.Length()-1; i >= 0; --i) {
nsFontMetrics* fm = mFontMetrics[i];
nsFontMetrics* oldfm = fm;
// Destroy() isn't here because we want our device context to be
// notified
NS_RELEASE(fm); // this will reset fm to nullptr
// if the font is really gone, it would have called back in
// FontMetricsDeleted() and would have removed itself
if (mFontMetrics.IndexOf(oldfm) != mFontMetrics.NoIndex) {
// nope, the font is still there, so let's hold onto it too
NS_ADDREF(oldfm);
}
}
}
void
nsFontCache::Flush()
{
for (int32_t i = mFontMetrics.Length()-1; i >= 0; --i) {
nsFontMetrics* fm = mFontMetrics[i];
// Destroy() will unhook our device context from the fm so that we
// won't waste time in triggering the notification of
// FontMetricsDeleted() in the subsequent release
fm->Destroy();
NS_RELEASE(fm);
}
mFontMetrics.Clear();
}
nsDeviceContext::nsDeviceContext()
: mWidth(0), mHeight(0), mDepth(0),
mAppUnitsPerDevPixel(-1), mAppUnitsPerDevPixelAtUnitFullZoom(-1),
mAppUnitsPerPhysicalInch(-1),
mFullZoom(1.0f), mPrintingScale(1.0f)
{
MOZ_ASSERT(NS_IsMainThread(), "nsDeviceContext created off main thread");
}
nsDeviceContext::~nsDeviceContext()
{
if (mFontCache) {
mFontCache->Destroy();
}
}
already_AddRefed<nsFontMetrics>
nsDeviceContext::GetMetricsFor(const nsFont& aFont,
const nsFontMetrics::Params& aParams)
{
if (!mFontCache) {
mFontCache = new nsFontCache();
mFontCache->Init(this);
}
return mFontCache->GetMetricsFor(aFont, aParams);
}
nsresult
nsDeviceContext::FlushFontCache(void)
{
if (mFontCache)
mFontCache->Flush();
return NS_OK;
}
nsresult
nsDeviceContext::FontMetricsDeleted(const nsFontMetrics* aFontMetrics)
{
if (mFontCache) {
mFontCache->FontMetricsDeleted(aFontMetrics);
}
return NS_OK;
}
bool
nsDeviceContext::IsPrinterSurface()
{
return mPrintTarget != nullptr;
}
void
nsDeviceContext::SetDPI(double* aScale)
{
float dpi = -1.0f;
// Use the printing DC to determine DPI values, if we have one.
if (mDeviceContextSpec) {
dpi = mDeviceContextSpec->GetDPI();
mPrintingScale = mDeviceContextSpec->GetPrintingScale();
mAppUnitsPerDevPixelAtUnitFullZoom =
NS_lround((AppUnitsPerCSSPixel() * 96) / dpi);
} else {
// A value of -1 means use the maximum of 96 and the system DPI.
// A value of 0 means use the system DPI. A positive value is used as the DPI.
// This sets the physical size of a device pixel and thus controls the
// interpretation of physical units.
int32_t prefDPI = Preferences::GetInt("layout.css.dpi", -1);
if (prefDPI > 0) {
dpi = prefDPI;
} else if (mWidget) {
dpi = mWidget->GetDPI();
if (prefDPI < 0) {
dpi = std::max(96.0f, dpi);
}
} else {
dpi = 96.0f;
}
double devPixelsPerCSSPixel;
if (aScale && *aScale > 0.0) {
// if caller provided a scale, we just use it
devPixelsPerCSSPixel = *aScale;
} else {
// otherwise get from the widget, and return it in aScale for
// the caller to pass to child contexts if needed
CSSToLayoutDeviceScale scale =
mWidget ? mWidget->GetDefaultScale()
: CSSToLayoutDeviceScale(1.0);
devPixelsPerCSSPixel = scale.scale;
if (aScale) {
*aScale = devPixelsPerCSSPixel;
}
}
mAppUnitsPerDevPixelAtUnitFullZoom =
std::max(1, NS_lround(AppUnitsPerCSSPixel() / devPixelsPerCSSPixel));
}
NS_ASSERTION(dpi != -1.0, "no dpi set");
mAppUnitsPerPhysicalInch = NS_lround(dpi * mAppUnitsPerDevPixelAtUnitFullZoom);
UpdateAppUnitsForFullZoom();
}
nsresult
nsDeviceContext::Init(nsIWidget *aWidget)
{
nsresult rv = NS_OK;
if (mScreenManager && mWidget == aWidget)
return rv;
mWidget = aWidget;
SetDPI();
if (mScreenManager)
return rv;
mScreenManager = do_GetService("@mozilla.org/gfx/screenmanager;1", &rv);
return rv;
}
// XXX This is only for printing. We should make that obvious in the name.
already_AddRefed<gfxContext>
nsDeviceContext::CreateRenderingContext()
{
MOZ_ASSERT(IsPrinterSurface());
MOZ_ASSERT(mWidth > 0 && mHeight > 0);
RefPtr<PrintTarget> printingTarget = mPrintTarget;
#ifdef XP_MACOSX
// CreateRenderingContext() can be called (on reflow) after EndPage()
// but before BeginPage(). On OS X (and only there) mPrintTarget
// will in this case be null, because OS X printing surfaces are
// per-page, and therefore only truly valid between calls to BeginPage()
// and EndPage(). But we can get away with fudging things here, if need
// be, by using a cached copy.
if (!printingTarget) {
printingTarget = mCachedPrintTarget;
}
#endif
// This will usually be null, depending on the pref print.print_via_parent.
RefPtr<DrawEventRecorder> recorder;
mDeviceContextSpec->GetDrawEventRecorder(getter_AddRefs(recorder));
RefPtr<gfx::DrawTarget> dt =
printingTarget->MakeDrawTarget(gfx::IntSize(mWidth, mHeight), recorder);
if (!dt || !dt->IsValid()) {
gfxCriticalNote
<< "Failed to create draw target in device context sized "
<< mWidth << "x" << mHeight << " and pointers "
<< hexa(mPrintTarget) << " and " << hexa(printingTarget);
return nullptr;
}
#ifdef XP_MACOSX
dt->AddUserData(&gfxContext::sDontUseAsSourceKey, dt, nullptr);
#endif
dt->AddUserData(&sDisablePixelSnapping, (void*)0x1, nullptr);
RefPtr<gfxContext> pContext = gfxContext::CreateOrNull(dt);
MOZ_ASSERT(pContext); // already checked draw target above
gfxMatrix transform;
if (printingTarget->RotateNeededForLandscape()) {
// Rotate page 90 degrees to draw landscape page on portrait paper
IntSize size = printingTarget->GetSize();
transform.Translate(gfxPoint(0, size.width));
gfxMatrix rotate(0, -1,
1, 0,
0, 0);
transform = rotate * transform;
}
transform.Scale(mPrintingScale, mPrintingScale);
pContext->SetMatrix(transform);
return pContext.forget();
}
nsresult
nsDeviceContext::GetDepth(uint32_t& aDepth)
{
if (mDepth == 0 && mScreenManager) {
nsCOMPtr<nsIScreen> primaryScreen;
mScreenManager->GetPrimaryScreen(getter_AddRefs(primaryScreen));
primaryScreen->GetColorDepth(reinterpret_cast<int32_t *>(&mDepth));
}
aDepth = mDepth;
return NS_OK;
}
nsresult
nsDeviceContext::GetDeviceSurfaceDimensions(nscoord &aWidth, nscoord &aHeight)
{
if (mPrintTarget) {
// we have a printer device
aWidth = mWidth;
aHeight = mHeight;
} else {
nsRect area;
ComputeFullAreaUsingScreen(&area);
aWidth = area.width;
aHeight = area.height;
}
return NS_OK;
}
nsresult
nsDeviceContext::GetRect(nsRect &aRect)
{
if (mPrintTarget) {
// we have a printer device
aRect.x = 0;
aRect.y = 0;
aRect.width = mWidth;
aRect.height = mHeight;
} else
ComputeFullAreaUsingScreen ( &aRect );
return NS_OK;
}
nsresult
nsDeviceContext::GetClientRect(nsRect &aRect)
{
if (mPrintTarget) {
// we have a printer device
aRect.x = 0;
aRect.y = 0;
aRect.width = mWidth;
aRect.height = mHeight;
}
else
ComputeClientRectUsingScreen(&aRect);
return NS_OK;
}
nsresult
nsDeviceContext::InitForPrinting(nsIDeviceContextSpec *aDevice)
{
NS_ENSURE_ARG_POINTER(aDevice);
mDeviceContextSpec = aDevice;
mPrintTarget = aDevice->MakePrintTarget();
if (!mPrintTarget) {
return NS_ERROR_FAILURE;
}
Init(nullptr);
if (!CalcPrintingSize()) {
return NS_ERROR_FAILURE;
}
return NS_OK;
}
nsresult
nsDeviceContext::BeginDocument(const nsAString& aTitle,
const nsAString& aPrintToFileName,
int32_t aStartPage,
int32_t aEndPage)
{
nsresult rv = mPrintTarget->BeginPrinting(aTitle, aPrintToFileName);
if (NS_SUCCEEDED(rv) && mDeviceContextSpec) {
rv = mDeviceContextSpec->BeginDocument(aTitle, aPrintToFileName,
aStartPage, aEndPage);
}
return rv;
}
nsresult
nsDeviceContext::EndDocument(void)
{
nsresult rv = NS_OK;
if (mPrintTarget) {
rv = mPrintTarget->EndPrinting();
if (NS_SUCCEEDED(rv))
mPrintTarget->Finish();
}
if (mDeviceContextSpec)
mDeviceContextSpec->EndDocument();
return rv;
}
nsresult
nsDeviceContext::AbortDocument(void)
{
nsresult rv = mPrintTarget->AbortPrinting();
if (mDeviceContextSpec)
mDeviceContextSpec->EndDocument();
return rv;
}
nsresult
nsDeviceContext::BeginPage(void)
{
nsresult rv = NS_OK;
if (mDeviceContextSpec)
rv = mDeviceContextSpec->BeginPage();
if (NS_FAILED(rv)) return rv;
#ifdef XP_MACOSX
// We need to get a new surface for each page on the Mac, as the
// CGContextRefs are only good for one page.
mPrintTarget = mDeviceContextSpec->MakePrintTarget();
#endif
rv = mPrintTarget->BeginPage();
return rv;
}
nsresult
nsDeviceContext::EndPage(void)
{
nsresult rv = mPrintTarget->EndPage();
#ifdef XP_MACOSX
// We need to release the CGContextRef in the surface here, plus it's
// not something you would want anyway, as these CGContextRefs are only
// good for one page. But we need to keep a cached reference to it, since
// CreateRenderingContext() may try to access it when mPrintTarget
// would normally be null. See bug 665218. If we just stop nulling out
// mPrintTarget here (and thereby make that our cached copy), we'll
// break all our null checks on mPrintTarget. See bug 684622.
mCachedPrintTarget = mPrintTarget;
mPrintTarget = nullptr;
#endif
if (mDeviceContextSpec)
mDeviceContextSpec->EndPage();
return rv;
}
void
nsDeviceContext::ComputeClientRectUsingScreen(nsRect* outRect)
{
// we always need to recompute the clientRect
// because the window may have moved onto a different screen. In the single
// monitor case, we only need to do the computation if we haven't done it
// once already, and remember that we have because we're assured it won't change.
nsCOMPtr<nsIScreen> screen;
FindScreen (getter_AddRefs(screen));
if (screen) {
int32_t x, y, width, height;
screen->GetAvailRect(&x, &y, &width, &height);
// convert to device units
outRect->y = NSIntPixelsToAppUnits(y, AppUnitsPerDevPixel());
outRect->x = NSIntPixelsToAppUnits(x, AppUnitsPerDevPixel());
outRect->width = NSIntPixelsToAppUnits(width, AppUnitsPerDevPixel());
outRect->height = NSIntPixelsToAppUnits(height, AppUnitsPerDevPixel());
}
}
void
nsDeviceContext::ComputeFullAreaUsingScreen(nsRect* outRect)
{
// if we have more than one screen, we always need to recompute the clientRect
// because the window may have moved onto a different screen. In the single
// monitor case, we only need to do the computation if we haven't done it
// once already, and remember that we have because we're assured it won't change.
nsCOMPtr<nsIScreen> screen;
FindScreen ( getter_AddRefs(screen) );
if ( screen ) {
int32_t x, y, width, height;
screen->GetRect ( &x, &y, &width, &height );
// convert to device units
outRect->y = NSIntPixelsToAppUnits(y, AppUnitsPerDevPixel());
outRect->x = NSIntPixelsToAppUnits(x, AppUnitsPerDevPixel());
outRect->width = NSIntPixelsToAppUnits(width, AppUnitsPerDevPixel());
outRect->height = NSIntPixelsToAppUnits(height, AppUnitsPerDevPixel());
mWidth = outRect->width;
mHeight = outRect->height;
}
}
//
// FindScreen
//
// Determines which screen intersects the largest area of the given surface.
//
void
nsDeviceContext::FindScreen(nsIScreen** outScreen)
{
if (!mWidget || !mScreenManager) {
return;
}
CheckDPIChange();
if (mWidget->GetOwningTabChild()) {
mScreenManager->ScreenForNativeWidget((void *)mWidget->GetOwningTabChild(),
outScreen);
}
else if (mWidget->GetNativeData(NS_NATIVE_WINDOW)) {
mScreenManager->ScreenForNativeWidget(mWidget->GetNativeData(NS_NATIVE_WINDOW),
outScreen);
}
else {
mScreenManager->GetPrimaryScreen(outScreen);
}
}
bool
nsDeviceContext::CalcPrintingSize()
{
if (!mPrintTarget) {
return (mWidth > 0 && mHeight > 0);
}
gfxSize size = mPrintTarget->GetSize();
// For printing, CSS inches and physical inches are identical
// so it doesn't matter which we use here
mWidth = NSToCoordRound(size.width * AppUnitsPerPhysicalInch()
/ POINTS_PER_INCH_FLOAT);
mHeight = NSToCoordRound(size.height * AppUnitsPerPhysicalInch()
/ POINTS_PER_INCH_FLOAT);
return (mWidth > 0 && mHeight > 0);
}
bool nsDeviceContext::CheckDPIChange(double* aScale)
{
int32_t oldDevPixels = mAppUnitsPerDevPixelAtUnitFullZoom;
int32_t oldInches = mAppUnitsPerPhysicalInch;
SetDPI(aScale);
return oldDevPixels != mAppUnitsPerDevPixelAtUnitFullZoom ||
oldInches != mAppUnitsPerPhysicalInch;
}
bool
nsDeviceContext::SetFullZoom(float aScale)
{
if (aScale <= 0) {
NS_NOTREACHED("Invalid full zoom value");
return false;
}
int32_t oldAppUnitsPerDevPixel = mAppUnitsPerDevPixel;
mFullZoom = aScale;
UpdateAppUnitsForFullZoom();
return oldAppUnitsPerDevPixel != mAppUnitsPerDevPixel;
}
void
nsDeviceContext::UpdateAppUnitsForFullZoom()
{
mAppUnitsPerDevPixel =
std::max(1, NSToIntRound(float(mAppUnitsPerDevPixelAtUnitFullZoom) / mFullZoom));
// adjust mFullZoom to reflect appunit rounding
mFullZoom = float(mAppUnitsPerDevPixelAtUnitFullZoom) / mAppUnitsPerDevPixel;
}
DesktopToLayoutDeviceScale
nsDeviceContext::GetDesktopToDeviceScale()
{
nsCOMPtr<nsIScreen> screen;
FindScreen(getter_AddRefs(screen));
if (screen) {
double scale;
screen->GetContentsScaleFactor(&scale);
return DesktopToLayoutDeviceScale(scale);
}
return DesktopToLayoutDeviceScale(1.0);
}