From 4f0cced6b40429dd432b1cb878b935bc51c921b8 Mon Sep 17 00:00:00 2001 From: Vadim Lopatin Date: Thu, 24 Dec 2015 17:40:41 +0300 Subject: [PATCH] css parser --- src/dlangui/core/css.d | 100 ++++++++++++++++++++++----- src/dlangui/core/cssparser.d | 127 ++++++++++++++++++++++++++++++----- 2 files changed, 195 insertions(+), 32 deletions(-) diff --git a/src/dlangui/core/css.d b/src/dlangui/core/css.d index c269bd5e..e5dbd27a 100644 --- a/src/dlangui/core/css.d +++ b/src/dlangui/core/css.d @@ -5,6 +5,9 @@ This module contains implementation of CSS support - Cascading Style Sheets. Port of CoolReader Engine written in C++. +Supports subset of CSS standards. + + Synopsis: ---- @@ -324,7 +327,7 @@ public: @property CssSelectorRule next() { return _next; } @property void next(CssSelectorRule v) { _next = v; } /// check condition for node - bool check(ref Node node) { + bool check(ref Node node) const { if (!node || !node.parent) return false; switch (_type) with (CssSelectorRuleType) { @@ -422,17 +425,17 @@ public: @property void id(elem_id id) { _id = id; } this() { } + ~this() { //if (_next) // destroy(_next); - //if (_rules) - // destroy(_rules); } void insertRuleStart(CssSelectorRule rule) { rule.next = _rules; _rules = rule; } + void insertRuleAfterStart(CssSelectorRule rule) { if (!_rules) { _rules = rule; @@ -442,26 +445,26 @@ public: } } - @property uint tagId() { return _id; } - bool check(const Node node) const { - // TODO - return false; + /// check if selector rules match this node + bool check(Node node) const { + CssSelectorRule rule = cast(CssSelectorRule)_rules; + while (rule && node) { + if (!rule.check(node)) + return false; + rule = rule.next; + } + return true; } + /// apply to style if selector matches - void apply(const Node node, CssStyle style) const - { + void apply(Node node, CssStyle style) const { if (check(node)) _decl.apply(style); } - void setDeclaration(CssDeclaration decl) { + + void setDeclaration(CssDeclaration decl) { _decl = decl; } - int getSpecificity() { - return _specificity; - } - @property CssSelector next() { return _next; } - @property void next(CssSelector next) { _next = next; } - //lUInt32 getHash(); } struct CssDeclItem { @@ -555,6 +558,71 @@ class CssDeclaration { } } +/// CSS Style Sheet +class StyleSheet { +private: + CssSelector[elem_id] _selectorMap; + int _len; +public: + /// clears stylesheet + void clear() { + _selectorMap = null; + _len = 0; + } + + /// count of selectors in stylesheet + @property int length() { return _len; } + + /// add selector to stylesheet + void add(CssSelector selector) { + elem_id id = selector.id; + if (auto p = id in _selectorMap) { + for (;;) { + if (!(*p) || (*p)._specificity < selector._specificity) { + selector._next = (*p); + (*p) = selector; + _len++; + break; + } + p = &((*p)._next); + } + } else { + // first selector for this id + _selectorMap[id] = selector; + _len++; + } + } + + /// apply stylesheet to node style + void apply(Node node, CssStyle style) { + elem_id id = node.id; + CssSelector selector_0, selector_id; + if (auto p = 0 in _selectorMap) + selector_0 = *p; + if (id) { + if (auto p = id in _selectorMap) + selector_id = *p; + } + for (;;) { + if (selector_0) { + if (!selector_id || selector_id._specificity < selector_0._specificity) { + selector_0.apply(node, style); + selector_0 = selector_0._next; + } else { + selector_id.apply(node, style); + selector_id = selector_id._next; + } + } else if (selector_id) { + selector_id.apply(node, style); + selector_id = selector_id._next; + } else { + // end of lists + break; + } + } + } +} + unittest { CssStyle style = new CssStyle(); CssWhiteSpace whiteSpace = CssWhiteSpace.inherit; diff --git a/src/dlangui/core/cssparser.d b/src/dlangui/core/cssparser.d index 932e5ad0..669837b3 100644 --- a/src/dlangui/core/cssparser.d +++ b/src/dlangui/core/cssparser.d @@ -20,27 +20,42 @@ private char skip(ref string src, int count = 1) { return src[0]; } -/// returns first char of string or 0 if end of string reached -private char peek(string str) { - return str.empty ? 0 : str[0]; +/// returns char of string at specified position (first by default) or 0 if end of string reached +private char peek(string str, int offset = 0) { + return offset >= str.length ? 0 : str[offset]; } /// skip spaces, move to new location, return first character in string, 0 if end of string reached -private char skipSpaces(ref string src) { - for(;;) { - if (src.empty) { - src = null; +private char skipSpaces(ref string str) +{ + string oldpos = str; + for (;;) { + char ch = str.peek; + if (!ch) return 0; + while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r') + ch = str.skip; + if (str.peek == '/' && str.peek(1) == '*') { + // comment found + str.skip(2); + while (str.peek && (str.peek(0) != '*' || str.peek(1) != '/')) + str.skip; + if (str.peek == '*' && str.peek(1) == '/' ) + str.skip(2); } - char ch = src[0]; - if (ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n') { - src.skip; - } else { - return src.empty ? 0 : src[0]; - } + ch = str.peek; + while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r') + ch = str.skip; + if (oldpos.ptr is str.ptr) + break; + if (str.empty) + return 0; + oldpos = str; } + return str.peek; } + private bool isIdentChar(char ch) { return (ch >= 'A' && ch <='Z') || (ch >= 'a' && ch <='z') || (ch == '-') || (ch == '_'); } @@ -62,7 +77,7 @@ private string parseIdent(ref string src) { private bool skipChar(ref string src, char ch) { src.skipSpaces; - if (src.length > 0 && src[0] == ch) { + if (src.peek == ch) { src.skip; src.skipSpaces; return true; @@ -506,6 +521,7 @@ private CssSelectorRule parseAttr(ref string str, Document doc) return rule; } +/// Parse css properties declaration either in {} or w/o {} - e.g. { width: 40%; margin-top: 3px } -- returns null if parse error occured or property list is empty CssDeclaration parseCssDeclaration(ref string src, bool mustBeInBrackets = true) { if (!src.skipSpaces) return null; @@ -688,7 +704,7 @@ CssDeclaration parseCssDeclaration(ref string src, bool mustBeInBrackets = true) return res; } -/// parse Css selector, return selector object if parsed ok +/// parse Css selector, return selector object if parsed ok, null if error occured CssSelector parseCssSelector(ref string str, Document doc) { if (str.empty) return null; @@ -756,6 +772,17 @@ CssSelector parseCssSelector(ref string str, Document doc) { } } +/// skips until } or end of string, returns true if some characters left in string +private bool skipUntilEndOfRule(ref string str) +{ + while (str.length && str[0] != '}') + str.skip; + if (str.peek == '}') + str.skip; + return !str.empty; +} + + unittest { Document doc = new Document(); string str; @@ -768,4 +795,72 @@ unittest { str = ".myclass + div { }"; assert(parseCssSelector(str, doc) !is null); assert(parseCssDeclaration(str, true) is null); // empty property decl -} \ No newline at end of file + destroy(doc); +} + +/// parse stylesheet text +bool parseStyleSheet(StyleSheet sheet, Document doc, string str) { + bool res = false; + for(;;) { + if (!str.skipSpaces) + break; + CssSelector[] selectors; + for(;;) { + CssSelector selector = parseCssSelector(str, doc); + if (!selector) + break; + selectors ~= selector; + str.skipChar(','); + } + if (selectors.length) { + if (CssDeclaration decl = parseCssDeclaration(str, true)) { + foreach(item; selectors) { + item.setDeclaration(decl); + sheet.add(item); + res = true; + } + } + } + if (!skipUntilEndOfRule(str)) + break; + } + return res; +} + +unittest { + string src = q{ + body { width: 50%; color: blue } + body > div, body > section { + /* some comment + goes here */ + font-family: serif; + background-color: yellow; + } + section { + margin-top: 5px + } + }; + Document doc = new Document(); + StyleSheet sheet = new StyleSheet(); + assert(parseStyleSheet(sheet, doc, src)); + assert(sheet.length == 2); + // check appending of additional source text + assert(parseStyleSheet(sheet, doc, "pre { white-space: pre }")); + assert(sheet.length == 3); + destroy(doc); +} + +unittest { + Document doc = new Document(); + StyleSheet sheet = new StyleSheet(); + assert(parseStyleSheet(sheet, doc, "* { color: #aaa }")); + assert(sheet.length == 1); + assert(parseStyleSheet(sheet, doc, "div, p { display: block }")); + assert(sheet.length == 3); + // check appending of additional source text + assert(parseStyleSheet(sheet, doc, "pre { white-space: pre }")); + assert(sheet.length == 4); + assert(parseStyleSheet(sheet, doc, "pre { font-size: 120% }")); + assert(sheet.length == 5); + destroy(doc); +}