Begin implementing codeblocks feature

1 files changed, 224 insertions, 0 deletions

diff --git a/main/src/ui/conversation_content_view/code_block_widget.vala b/main/src/ui/conversation_content_view/code_block_widget.vala
new file mode 100644
index 00000000..dc1ecc1f
--- /dev/null
+++ b/main/src/ui/conversation_content_view/code_block_widget.vala
@@ -0,0 +1,224 @@
+using Gee;
+using Gdk;
+using Gtk;
+using Pango;
+
+namespace Dino.Ui.ConversationSummary {
+
+public class CodeBlockPart : Object {
+    public bool is_code;
+    public string text;
+    public string language;
+    public int source_start_char;
+
+    public CodeBlockPart.from_text(string text, int source_start_char) {
+        this.text = text;
+        this.source_start_char = source_start_char;
+        this.language = "";
+    }
+
+    public CodeBlockPart.from_code(string text, string language) {
+        this.is_code = true;
+        this.text = text;
+        this.language = language;
+    }
+}
+
+public class CodeBlockParser : Object {
+    private static Regex? fence_regex;
+
+    public static ArrayList<CodeBlockPart> parse(string text, out bool has_blocks) {
+        var parts = new ArrayList<CodeBlockPart>();
+        Regex regex = get_fence_regex();
+        MatchInfo match_info;
+        int offset = 0;
+        has_blocks = false;
+        try {
+            regex.match_full(text, -1, offset, 0, out match_info);
+        } catch (RegexError error) {
+            parts.add(new CodeBlockPart.from_text(text, 0));
+            return parts;
+        }
+        while (match_info.matches()) {
+            int match_start;
+            int match_end;
+            int code_start;
+            int code_end;
+            match_info.fetch_pos(0, out match_start, out match_end);
+            match_info.fetch_pos(2, out code_start, out code_end);
+            int text_end = match_start;
+            if (text_end > offset && text[text_end - 1] == '\n') {
+                text_end--;
+                if (text_end > offset && text[text_end - 1] == '\r') text_end--;
+            }
+            if (text_end > offset) {
+                parts.add(new CodeBlockPart.from_text(text.substring(offset, text_end - offset), text.substring(0, offset).char_count()));
+            }
+            if (code_end > code_start && text[code_end - 1] == '\n') {
+                code_end--;
+                if (code_end > code_start && text[code_end - 1] == '\r') code_end--;
+            }
+            string code = text.substring(code_start, code_end - code_start).replace("\r\n", "\n");
+            parts.add(new CodeBlockPart.from_code(code, match_info.fetch(1).strip()));
+            has_blocks = true;
+            offset = match_end;
+            if (offset >= text.length) break;
+            try {
+                regex.match_full(text, -1, offset, 0, out match_info);
+            } catch (RegexError error) {
+                break;
+            }
+        }
+        if (offset < text.length) {
+            parts.add(new CodeBlockPart.from_text(text.substring(offset), text.substring(0, offset).char_count()));
+        }
+        return parts;
+    }
+
+    private static Regex get_fence_regex() {
+        if (fence_regex == null) {
+            try {
+                fence_regex = new Regex("(?ms)^```[\\t ]*([^\\r\\n`]*)[\\t ]*\\r?\\n(.*?)^```[\\t ]*(?:\\r?\\n|$)", RegexCompileFlags.OPTIMIZE);
+            } catch (RegexError error) {
+                GLib.error("Invalid code block expression: %s", error.message);
+            }
+        }
+        return fence_regex;
+    }
+}
+
+public class CodeBlockWidget : Box {
+    private string code;
+    private CodeSyntax.LanguageDefinition? definition;
+    private Label code_label;
+    private ulong realize_id;
+
+    public CodeBlockWidget(string code, string language) {
+        Object(orientation: Orientation.VERTICAL, spacing: 0, halign: Align.START, overflow: Overflow.HIDDEN);
+        this.code = code;
+        definition = CodeSyntax.find(language);
+        add_css_class("code-block");
+
+        var header = new Box(Orientation.HORIZONTAL, 8);
+        header.add_css_class("code-block-header");
+
+        string language_name = definition != null ? definition.name : language.strip();
+        if (language_name == "") language_name = _("Plain text");
+        var language_label = new Label(language_name) { xalign=0, hexpand=true };
+        language_label.add_css_class("code-block-language");
+        header.append(language_label);
+
+        int line_count = code == "" ? 0 : code.split("\n").length;
+        var line_label = new Label(n("%d line", "%d lines", line_count).printf(line_count));
+        line_label.add_css_class("code-block-meta");
+        header.append(line_label);
+
+        var download_button = new Button.from_icon_name("dino-file-download-symbolic") {
+            tooltip_text=_("Download code")
+        };
+        download_button.add_css_class("flat");
+        download_button.add_css_class("code-block-download");
+        download_button.clicked.connect(save);
+        header.append(download_button);
+        append(header);
+
+        code_label = new Label(code) {
+            use_markup=false,
+            selectable=true,
+            xalign=0,
+            yalign=0,
+            wrap=false
+        };
+        code_label.add_css_class("code-block-content");
+        append(code_label);
+
+        apply_highlighting();
+        realize_id = realize.connect(apply_highlighting);
+    }
+
+    private void apply_highlighting() {
+        var attributes = new AttrList();
+        if (definition != null) {
+            foreach (CodeSyntax.HighlightSpan span in definition.highlight(code)) {
+                RGBA color = get_token_color(span.style);
+                Attribute foreground = Pango.attr_foreground_new(
+                    (uint16) Math.round(color.red * uint16.MAX),
+                    (uint16) Math.round(color.green * uint16.MAX),
+                    (uint16) Math.round(color.blue * uint16.MAX)
+                );
+                foreground.start_index = span.start;
+                foreground.end_index = span.end;
+                attributes.insert(foreground.copy());
+                if (color.alpha < 1) {
+                    Attribute alpha = Pango.attr_foreground_alpha_new((uint16) Math.round(color.alpha * uint16.MAX));
+                    alpha.start_index = span.start;
+                    alpha.end_index = span.end;
+                    attributes.insert(alpha.copy());
+                }
+            }
+        }
+        code_label.attributes = attributes;
+    }
+
+    private RGBA get_token_color(CodeSyntax.TokenStyle style) {
+        StyleContext context = code_label.get_style_context();
+        RGBA color = context.get_color();
+        string? color_name = null;
+        switch (style) {
+            case CodeSyntax.TokenStyle.COMMENT:
+                color.alpha = 0.62f;
+                break;
+            case CodeSyntax.TokenStyle.CONSTANT:
+                color_name = "error_color";
+                break;
+            case CodeSyntax.TokenStyle.NUMBER:
+            case CodeSyntax.TokenStyle.PREPROCESSOR:
+                color_name = "warning_color";
+                break;
+            case CodeSyntax.TokenStyle.STRING:
+            case CodeSyntax.TokenStyle.TYPE:
+                color_name = "success_color";
+                break;
+            case CodeSyntax.TokenStyle.FUNCTION:
+            case CodeSyntax.TokenStyle.KEYWORD:
+                color_name = "accent_color";
+                break;
+        }
+        if (color_name != null) {
+            RGBA theme_color;
+            if (context.lookup_color(color_name, out theme_color)) color = theme_color;
+        }
+        return color;
+    }
+
+    private void save() {
+        var dialog = new FileChooserNative(_("Save code as…"), get_root() as Gtk.Window, FileChooserAction.SAVE, _("Save"), _("Cancel"));
+        dialog.modal = true;
+        dialog.set_current_name("code." + (definition != null ? definition.extension : "txt"));
+        dialog.response.connect((response_id) => {
+            if (response_id == ResponseType.ACCEPT) {
+                File? target = dialog.get_file();
+                if (target != null) {
+                    try {
+                        string? etag;
+                        target.replace_contents(code.data, null, false, FileCreateFlags.REPLACE_DESTINATION, out etag);
+                    } catch (Error error) {
+                        warning("Failed to save code: %s", error.message);
+                    }
+                }
+            }
+            dialog.destroy();
+        });
+        dialog.show();
+    }
+
+    public override void dispose() {
+        if (realize_id != 0) {
+            disconnect(realize_id);
+            realize_id = 0;
+        }
+        base.dispose();
+    }
+}
+
+}