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Diffstat (limited to 'layout/style/nsMediaFeatures.cpp')
| -rw-r--r-- | layout/style/nsMediaFeatures.cpp | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/layout/style/nsMediaFeatures.cpp b/layout/style/nsMediaFeatures.cpp new file mode 100644 index 0000000000..c99eecb486 --- /dev/null +++ b/layout/style/nsMediaFeatures.cpp @@ -0,0 +1,407 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/. */ + +/* the features that media queries can test */ + +#include "nsGkAtoms.h" +#include "nsStyleConsts.h" +#include "nsPresContext.h" +#include "nsCSSProps.h" +#include "nsCSSValue.h" +#include "mozilla/LookAndFeel.h" +#include "nsDeviceContext.h" +#include "nsIBaseWindow.h" +#include "nsIDocShell.h" +#include "nsIPrintSettings.h" +#include "mozilla/dom/Document.h" +#include "mozilla/dom/DocumentInlines.h" +#include "mozilla/dom/BrowsingContextBinding.h" +#include "mozilla/dom/ScreenBinding.h" +#include "nsIWidget.h" +#include "nsContentUtils.h" +#include "mozilla/RelativeLuminanceUtils.h" +#include "mozilla/StaticPrefs_browser.h" +#include "mozilla/StyleSheet.h" +#include "mozilla/StyleSheetInlines.h" +#include "mozilla/GeckoBindings.h" +#include "PreferenceSheet.h" +#include "nsGlobalWindowOuter.h" +#ifdef XP_WIN +# include "mozilla/WindowsVersion.h" +#endif + +using namespace mozilla; +using mozilla::dom::DisplayMode; +using mozilla::dom::Document; + +// A helper for four features below +static nsSize GetSize(const Document& aDocument) { + nsPresContext* pc = aDocument.GetPresContext(); + + // Per spec, return a 0x0 viewport if we're not being rendered. See: + // + // * https://github.com/w3c/csswg-drafts/issues/571 + // * https://github.com/whatwg/html/issues/1813 + // + if (!pc) { + return {}; + } + + if (pc->IsRootPaginatedDocument()) { + // We want the page size, including unprintable areas and margins. + // + // FIXME(emilio, bug 1414600): Not quite! + return pc->GetPageSize(); + } + + return pc->GetVisibleArea().Size(); +} + +// A helper for three features below. +static nsSize GetDeviceSize(const Document& aDocument) { + if (aDocument.ShouldResistFingerprinting(RFPTarget::CSSDeviceSize)) { + return GetSize(aDocument); + } + + // Media queries in documents in an RDM pane should use the simulated + // device size. + Maybe<CSSIntSize> deviceSize = + nsGlobalWindowOuter::GetRDMDeviceSize(aDocument); + if (deviceSize.isSome()) { + return CSSPixel::ToAppUnits(deviceSize.value()); + } + + nsPresContext* pc = aDocument.GetPresContext(); + // NOTE(emilio): We should probably figure out how to return an appropriate + // device size here, though in a multi-screen world that makes no sense + // really. + if (!pc) { + return {}; + } + + if (pc->IsRootPaginatedDocument()) { + // We want the page size, including unprintable areas and margins. + // XXX The spec actually says we want the "page sheet size", but + // how is that different? + return pc->GetPageSize(); + } + + nsSize size; + pc->DeviceContext()->GetDeviceSurfaceDimensions(size.width, size.height); + return size; +} + +bool Gecko_MediaFeatures_IsResourceDocument(const Document* aDocument) { + return aDocument->IsResourceDoc(); +} + +bool Gecko_MediaFeatures_UseOverlayScrollbars(const Document* aDocument) { + nsPresContext* pc = aDocument->GetPresContext(); + return pc && pc->UseOverlayScrollbars(); +} + +static nsDeviceContext* GetDeviceContextFor(const Document* aDocument) { + nsPresContext* pc = aDocument->GetPresContext(); + if (!pc) { + return nullptr; + } + + // It would be nice to call nsLayoutUtils::GetDeviceContextForScreenInfo here, + // except for two things: (1) it can flush, and flushing is bad here, and (2) + // it doesn't really get us consistency in multi-monitor situations *anyway*. + return pc->DeviceContext(); +} + +void Gecko_MediaFeatures_GetDeviceSize(const Document* aDocument, + nscoord* aWidth, nscoord* aHeight) { + nsSize size = GetDeviceSize(*aDocument); + *aWidth = size.width; + *aHeight = size.height; +} + +int32_t Gecko_MediaFeatures_GetMonochromeBitsPerPixel( + const Document* aDocument) { + // The default bits per pixel for a monochrome device. We could propagate this + // further to nsIPrintSettings, but Gecko doesn't actually know this value + // from the hardware, so it seems silly to do so. + static constexpr int32_t kDefaultMonochromeBpp = 8; + + nsPresContext* pc = aDocument->GetPresContext(); + if (!pc) { + return 0; + } + nsIPrintSettings* ps = pc->GetPrintSettings(); + if (!ps) { + return 0; + } + bool color = true; + ps->GetPrintInColor(&color); + return color ? 0 : kDefaultMonochromeBpp; +} + +dom::ScreenColorGamut Gecko_MediaFeatures_ColorGamut( + const Document* aDocument) { + auto colorGamut = dom::ScreenColorGamut::Srgb; + if (!aDocument->ShouldResistFingerprinting(RFPTarget::CSSColorInfo)) { + if (auto* dx = GetDeviceContextFor(aDocument)) { + colorGamut = dx->GetColorGamut(); + } + } + return colorGamut; +} + +int32_t Gecko_MediaFeatures_GetColorDepth(const Document* aDocument) { + if (Gecko_MediaFeatures_GetMonochromeBitsPerPixel(aDocument) != 0) { + // If we're a monochrome device, then the color depth is zero. + return 0; + } + + // Use depth of 24 when resisting fingerprinting, or when we're not being + // rendered. + int32_t depth = 24; + + if (!aDocument->ShouldResistFingerprinting(RFPTarget::CSSColorInfo)) { + if (nsDeviceContext* dx = GetDeviceContextFor(aDocument)) { + depth = dx->GetDepth(); + } + } + + // The spec says to use bits *per color component*, so divide by 3, + // and round down, since the spec says to use the smallest when the + // color components differ. + return depth / 3; +} + +float Gecko_MediaFeatures_GetResolution(const Document* aDocument) { + // We're returning resolution in terms of device pixels per css pixel, since + // that is the preferred unit for media queries of resolution. This avoids + // introducing precision error from conversion to and from less-used + // physical units like inches. + nsPresContext* pc = aDocument->GetPresContext(); + if (!pc) { + return 1.; + } + + if (pc->GetOverrideDPPX() > 0.) { + return pc->GetOverrideDPPX(); + } + + if (aDocument->ShouldResistFingerprinting(RFPTarget::CSSResolution)) { + return pc->DeviceContext()->GetFullZoom(); + } + // Get the actual device pixel ratio, which also takes zoom into account. + return float(AppUnitsPerCSSPixel()) / + pc->DeviceContext()->AppUnitsPerDevPixel(); +} + +static const Document* TopDocument(const Document* aDocument) { + const Document* current = aDocument; + while (const Document* parent = current->GetInProcessParentDocument()) { + current = parent; + } + return current; +} + +StyleDisplayMode Gecko_MediaFeatures_GetDisplayMode(const Document* aDocument) { + const Document* rootDocument = TopDocument(aDocument); + + nsCOMPtr<nsISupports> container = rootDocument->GetContainer(); + if (nsCOMPtr<nsIBaseWindow> baseWindow = do_QueryInterface(container)) { + nsCOMPtr<nsIWidget> mainWidget; + baseWindow->GetMainWidget(getter_AddRefs(mainWidget)); + if (mainWidget && mainWidget->SizeMode() == nsSizeMode_Fullscreen) { + return StyleDisplayMode::Fullscreen; + } + } + + static_assert(static_cast<int32_t>(DisplayMode::Browser) == + static_cast<int32_t>(StyleDisplayMode::Browser) && + static_cast<int32_t>(DisplayMode::Minimal_ui) == + static_cast<int32_t>(StyleDisplayMode::MinimalUi) && + static_cast<int32_t>(DisplayMode::Standalone) == + static_cast<int32_t>(StyleDisplayMode::Standalone) && + static_cast<int32_t>(DisplayMode::Fullscreen) == + static_cast<int32_t>(StyleDisplayMode::Fullscreen), + "DisplayMode must mach nsStyleConsts.h"); + + dom::BrowsingContext* browsingContext = aDocument->GetBrowsingContext(); + if (!browsingContext) { + return StyleDisplayMode::Browser; + } + return static_cast<StyleDisplayMode>(browsingContext->DisplayMode()); +} + +bool Gecko_MediaFeatures_MatchesPlatform(StylePlatform aPlatform) { + switch (aPlatform) { +#if defined(XP_WIN) + case StylePlatform::Windows: + return true; +#elif defined(ANDROID) + case StylePlatform::Android: + return true; +#elif defined(MOZ_WIDGET_GTK) + case StylePlatform::Linux: + return true; +#elif defined(XP_MACOSX) + case StylePlatform::Macos: + return true; +#else +# error "Unknown platform?" +#endif + default: + return false; + } +} + +bool Gecko_MediaFeatures_PrefersReducedMotion(const Document* aDocument) { + if (aDocument->ShouldResistFingerprinting( + RFPTarget::CSSPrefersReducedMotion)) { + return false; + } + return LookAndFeel::GetInt(LookAndFeel::IntID::PrefersReducedMotion, 0) == 1; +} + +bool Gecko_MediaFeatures_PrefersReducedTransparency(const Document* aDocument) { + if (aDocument->ShouldResistFingerprinting( + RFPTarget::CSSPrefersReducedTransparency)) { + return false; + } + return LookAndFeel::GetInt(LookAndFeel::IntID::PrefersReducedTransparency, + 0) == 1; +} + +StylePrefersColorScheme Gecko_MediaFeatures_PrefersColorScheme( + const Document* aDocument, bool aUseContent) { + auto scheme = aUseContent ? PreferenceSheet::ContentPrefs().mColorScheme + : aDocument->PreferredColorScheme(); + return scheme == ColorScheme::Dark ? StylePrefersColorScheme::Dark + : StylePrefersColorScheme::Light; +} + +// Neither Linux, Windows, nor Mac have a way to indicate that low contrast is +// preferred so we use the presence of an accessibility theme or forced colors +// as a signal. +StylePrefersContrast Gecko_MediaFeatures_PrefersContrast( + const Document* aDocument) { + if (aDocument->ShouldResistFingerprinting(RFPTarget::CSSPrefersContrast)) { + return StylePrefersContrast::NoPreference; + } + const auto& prefs = PreferenceSheet::PrefsFor(*aDocument); + if (!prefs.mUseAccessibilityTheme && prefs.mUseDocumentColors) { + return StylePrefersContrast::NoPreference; + } + const auto& colors = prefs.ColorsFor(ColorScheme::Light); + float ratio = RelativeLuminanceUtils::ContrastRatio(colors.mDefaultBackground, + colors.mDefault); + // https://www.w3.org/TR/WCAG21/#contrast-minimum + if (ratio < 4.5f) { + return StylePrefersContrast::Less; + } + // https://www.w3.org/TR/WCAG21/#contrast-enhanced + if (ratio >= 7.0f) { + return StylePrefersContrast::More; + } + return StylePrefersContrast::Custom; +} + +bool Gecko_MediaFeatures_InvertedColors(const Document* aDocument) { + if (aDocument->ShouldResistFingerprinting(RFPTarget::CSSInvertedColors)) { + return false; + } + return LookAndFeel::GetInt(LookAndFeel::IntID::InvertedColors, 0) == 1; +} + +StyleScripting Gecko_MediaFeatures_Scripting(const Document* aDocument) { + const auto* doc = aDocument; + if (aDocument->IsStaticDocument()) { + doc = aDocument->GetOriginalDocument(); + } + + return doc->IsScriptEnabled() ? StyleScripting::Enabled + : StyleScripting::None; +} + +StyleDynamicRange Gecko_MediaFeatures_DynamicRange(const Document* aDocument) { + // Bug 1759772: Once HDR color is available, update each platform + // LookAndFeel implementation to return StyleDynamicRange::High when + // appropriate. + return StyleDynamicRange::Standard; +} + +StyleDynamicRange Gecko_MediaFeatures_VideoDynamicRange( + const Document* aDocument) { + if (aDocument->ShouldResistFingerprinting(RFPTarget::CSSVideoDynamicRange)) { + return StyleDynamicRange::Standard; + } + // video-dynamic-range: high has 3 requirements: + // 1) high peak brightness + // 2) high contrast ratio + // 3) color depth > 24 + // We check the color depth requirement before asking the LookAndFeel + // if it is HDR capable. + if (nsDeviceContext* dx = GetDeviceContextFor(aDocument)) { + if (dx->GetDepth() > 24 && + LookAndFeel::GetInt(LookAndFeel::IntID::VideoDynamicRange)) { + return StyleDynamicRange::High; + } + } + + return StyleDynamicRange::Standard; +} + +static PointerCapabilities GetPointerCapabilities(const Document* aDocument, + LookAndFeel::IntID aID) { + MOZ_ASSERT(aID == LookAndFeel::IntID::PrimaryPointerCapabilities || + aID == LookAndFeel::IntID::AllPointerCapabilities); + MOZ_ASSERT(aDocument); + + if (dom::BrowsingContext* bc = aDocument->GetBrowsingContext()) { + // The touch-events-override happens only for the Responsive Design Mode so + // that we don't need to care about ResistFingerprinting. + if (bc->TouchEventsOverride() == dom::TouchEventsOverride::Enabled) { + return PointerCapabilities::Coarse; + } + } + + // The default value for Desktop is mouse-type pointer, and for Android + // a coarse pointer. + const PointerCapabilities kDefaultCapabilities = +#ifdef ANDROID + PointerCapabilities::Coarse; +#else + PointerCapabilities::Fine | PointerCapabilities::Hover; +#endif + if (aDocument->ShouldResistFingerprinting( + RFPTarget::CSSPointerCapabilities)) { + return kDefaultCapabilities; + } + + int32_t intValue; + nsresult rv = LookAndFeel::GetInt(aID, &intValue); + if (NS_FAILED(rv)) { + return kDefaultCapabilities; + } + + return static_cast<PointerCapabilities>(intValue); +} + +PointerCapabilities Gecko_MediaFeatures_PrimaryPointerCapabilities( + const Document* aDocument) { + return GetPointerCapabilities(aDocument, + LookAndFeel::IntID::PrimaryPointerCapabilities); +} + +PointerCapabilities Gecko_MediaFeatures_AllPointerCapabilities( + const Document* aDocument) { + return GetPointerCapabilities(aDocument, + LookAndFeel::IntID::AllPointerCapabilities); +} + +StyleGtkThemeFamily Gecko_MediaFeatures_GtkThemeFamily() { + static_assert(int32_t(StyleGtkThemeFamily::Unknown) == 0); + return StyleGtkThemeFamily( + LookAndFeel::GetInt(LookAndFeel::IntID::GTKThemeFamily)); +} |