Begin implementing codeblocks feature

1 files changed, 136 insertions, 0 deletions

diff --git a/main/src/ui/conversation_content_view/syntax_highlighting.vala b/main/src/ui/conversation_content_view/syntax_highlighting.vala
new file mode 100644
index 00000000..b45ba81c
--- /dev/null
+++ b/main/src/ui/conversation_content_view/syntax_highlighting.vala
@@ -0,0 +1,136 @@
+using Gee;
+
+namespace Dino.Ui.CodeSyntax {
+
+public enum TokenStyle {
+    COMMENT,
+    CONSTANT,
+    FUNCTION,
+    KEYWORD,
+    NUMBER,
+    PREPROCESSOR,
+    STRING,
+    TYPE
+}
+
+public class HighlightSpan : Object {
+    public int start;
+    public int end;
+    public TokenStyle style;
+
+    public HighlightSpan(int start, int end, TokenStyle style) {
+        this.start = start;
+        this.end = end;
+        this.style = style;
+    }
+}
+
+public class HighlightRule : Object {
+    public TokenStyle style;
+    private Regex regex;
+
+    public HighlightRule(TokenStyle style, string pattern) {
+        this.style = style;
+        try {
+            regex = new Regex(pattern, RegexCompileFlags.OPTIMIZE);
+        } catch (RegexError error) {
+            GLib.error("Invalid syntax highlighting rule: %s", error.message);
+        }
+    }
+
+    public bool find(string text, int offset, out int start, out int end) {
+        MatchInfo match_info;
+        try {
+            regex.match_full(text, -1, offset, 0, out match_info);
+        } catch (RegexError error) {
+            start = -1;
+            end = -1;
+            return false;
+        }
+        if (!match_info.matches()) {
+            start = -1;
+            end = -1;
+            return false;
+        }
+        match_info.fetch_pos(0, out start, out end);
+        return true;
+    }
+}
+
+public class LanguageDefinition : Object {
+    public string id;
+    public string name;
+    public string extension;
+    public string[] aliases;
+    public HighlightRule[] rules;
+
+    public LanguageDefinition(string id, string name, string extension, string[] aliases, HighlightRule[] rules) {
+        this.id = id;
+        this.name = name;
+        this.extension = extension;
+        this.aliases = aliases;
+        this.rules = rules;
+    }
+
+    public bool matches(string language) {
+        string normalized = language.down().strip();
+        if (normalized == id) return true;
+        foreach (string alias in aliases) {
+            if (normalized == alias) return true;
+        }
+        return false;
+    }
+
+    public ArrayList<HighlightSpan> highlight(string text) {
+        var spans = new ArrayList<HighlightSpan>();
+        int offset = 0;
+        while (offset < text.length) {
+            HighlightRule? selected_rule = null;
+            int selected_start = text.length;
+            int selected_end = text.length;
+            foreach (HighlightRule rule in rules) {
+                int start;
+                int end;
+                if (rule.find(text, offset, out start, out end) && start < selected_start) {
+                    selected_rule = rule;
+                    selected_start = start;
+                    selected_end = end;
+                }
+            }
+            if (selected_rule == null || selected_end <= selected_start) break;
+            spans.add(new HighlightSpan(selected_start, selected_end, selected_rule.style));
+            offset = selected_end;
+        }
+        return spans;
+    }
+}
+
+private static LanguageDefinition[]? definitions;
+
+public static LanguageDefinition? find(string language) {
+    if (definitions == null) definitions = create_definitions();
+    foreach (LanguageDefinition definition in definitions) {
+        if (definition.matches(language)) return definition;
+    }
+    return null;
+}
+
+private static LanguageDefinition[] create_definitions() {
+    return { create_c_definition() };
+}
+
+private static LanguageDefinition create_c_definition() {
+    HighlightRule[] rules = {
+        new HighlightRule(TokenStyle.COMMENT, "//[^\\r\\n]*|/\\*[\\s\\S]*?\\*/"),
+        new HighlightRule(TokenStyle.STRING, "\"(?:\\\\.|[^\"\\\\])*\"|'(?:\\\\.|[^'\\\\])*'"),
+        new HighlightRule(TokenStyle.PREPROCESSOR, "(?m)^[\\t ]*#[\\t ]*[A-Za-z_][A-Za-z0-9_]*"),
+        new HighlightRule(TokenStyle.KEYWORD, "\\b(?:alignas|alignof|asm|auto|break|case|const|constexpr|continue|default|do|else|enum|extern|for|goto|if|inline|register|restrict|return|sizeof|static|static_assert|struct|switch|thread_local|typedef|typeof|typeof_unqual|union|volatile|while|_Alignas|_Alignof|_Atomic|_Generic|_Noreturn|_Static_assert|_Thread_local)\\b"),
+        new HighlightRule(TokenStyle.TYPE, "\\b(?:bool|char|char8_t|double|float|int|long|short|signed|unsigned|void|_Bool|_Complex|_Decimal32|_Decimal64|_Decimal128|_Imaginary|int8_t|int16_t|int32_t|int64_t|uint8_t|uint16_t|uint32_t|uint64_t|intptr_t|uintptr_t|ptrdiff_t|size_t|ssize_t|wchar_t)\\b"),
+        new HighlightRule(TokenStyle.CONSTANT, "\\b(?:false|NULL|nullptr|true)\\b"),
+        new HighlightRule(TokenStyle.NUMBER, "\\b(?:0[xX][0-9A-Fa-f]+|0[bB][01]+|(?:[0-9]+\\.[0-9]*|[0-9]+)(?:[eEpP][+-]?[0-9]+)?)[fFlLuU]*\\b"),
+        new HighlightRule(TokenStyle.FUNCTION, "\\b[A-Za-z_][A-Za-z0-9_]*(?=[\\t ]*\\()")
+    };
+    return new LanguageDefinition("c", "C", "c", { "h", "c89", "c90", "c99", "c11", "c17", "c18", "c23" }, rules);
+}
+
+}