1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/style/nsMediaFeatures.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,75 @@
1.4 +/* vim: set shiftwidth=4 tabstop=8 autoindent cindent expandtab: */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* the features that media queries can test */
1.10 +
1.11 +#ifndef nsMediaFeatures_h_
1.12 +#define nsMediaFeatures_h_
1.13 +
1.14 +#include "nsError.h"
1.15 +#include "nsCSSProps.h"
1.16 +
1.17 +class nsIAtom;
1.18 +class nsPresContext;
1.19 +class nsCSSValue;
1.20 +
1.21 +struct nsMediaFeature;
1.22 +typedef nsresult
1.23 +(* nsMediaFeatureValueGetter)(nsPresContext* aPresContext,
1.24 + const nsMediaFeature* aFeature,
1.25 + nsCSSValue& aResult);
1.26 +
1.27 +struct nsMediaFeature {
1.28 + nsIAtom **mName; // extra indirection to point to nsGkAtoms members
1.29 +
1.30 + enum RangeType { eMinMaxAllowed, eMinMaxNotAllowed };
1.31 + RangeType mRangeType;
1.32 +
1.33 + enum ValueType {
1.34 + // All value types allow eCSSUnit_Null to indicate that no value
1.35 + // was given (in addition to the types listed below).
1.36 + eLength, // values are such that nsCSSValue::IsLengthUnit() is true
1.37 + eInteger, // values are eCSSUnit_Integer
1.38 + eFloat, // values are eCSSUnit_Number
1.39 + eBoolInteger,// values are eCSSUnit_Integer (0, -0, or 1 only)
1.40 + eIntRatio, // values are eCSSUnit_Array of two eCSSUnit_Integer
1.41 + eResolution, // values are in eCSSUnit_Inch (for dpi),
1.42 + // eCSSUnit_Pixel (for dppx), or
1.43 + // eCSSUnit_Centimeter (for dpcm)
1.44 + eEnumerated, // values are eCSSUnit_Enumerated (uses keyword table)
1.45 + eIdent // values are eCSSUnit_Ident
1.46 + // Note that a number of pieces of code (both for parsing and
1.47 + // for matching of valueless expressions) assume that all numeric
1.48 + // value types cannot be negative. The parsing code also does
1.49 + // not allow zeros in eIntRatio types.
1.50 + };
1.51 + ValueType mValueType;
1.52 +
1.53 + union {
1.54 + // In static arrays, it's the first member that's initialized. We
1.55 + // need that to be void* so we can initialize both other types.
1.56 + // This member should never be accessed by name.
1.57 + const void* mInitializer_;
1.58 + // If mValueType == eEnumerated: const int32_t*: keyword table in
1.59 + // the same format as the keyword tables in nsCSSProps.
1.60 + const nsCSSProps::KTableValue* mKeywordTable;
1.61 + // If mGetter == GetSystemMetric (which implies mValueType ==
1.62 + // eBoolInteger): nsIAtom * const *, for the system metric.
1.63 + nsIAtom * const * mMetric;
1.64 + } mData;
1.65 +
1.66 + // A function that returns the current value for this feature for a
1.67 + // given presentation. If it returns eCSSUnit_Null, the feature is
1.68 + // not present.
1.69 + nsMediaFeatureValueGetter mGetter;
1.70 +};
1.71 +
1.72 +class nsMediaFeatures {
1.73 +public:
1.74 + // Terminated with an entry whose mName is null.
1.75 + static const nsMediaFeature features[];
1.76 +};
1.77 +
1.78 +#endif /* !defined(nsMediaFeatures_h_) */
