GeminiRenderer: restructure code; makes highlighting work on non-paragraphs

1 files changed, 328 insertions, 322 deletions

diff --git a/src/renderers/geminirenderer.cpp b/src/renderers/geminirenderer.cpp
index 0e62ef3..f81b12a 100644
--- a/src/renderers/geminirenderer.cpp
+++ b/src/renderers/geminirenderer.cpp
@@ -29,6 +29,7 @@ static QByteArray trim_whitespace(const QByteArray &items)
 }
 
 static QByteArray replace_quotes(QByteArray&);
+static void insertText(QTextCursor&, const QByteArray&, const QTextCharFormat&);
 
 std::unique_ptr<GeminiDocument> GeminiRenderer::render(
         const QByteArray &input,
@@ -43,8 +44,6 @@ std::unique_ptr<GeminiDocument> GeminiRenderer::render(
     renderhelpers::setPageMargins(result.get(), themed_style.margin_h, themed_style.margin_v);
     result->setIndentWidth(themed_style.indent_size);
 
-    bool emit_fancy_text = kristall::globals().options.enable_text_decoration;
-
     QTextCursor cursor{result.get()};
 
     bool verbatim = false;
@@ -86,370 +85,216 @@ std::unique_ptr<GeminiDocument> GeminiRenderer::render(
                 cursor.setCharFormat(text_style.preformatted);
                 cursor.insertText(line + "\n");
             }
+
+            continue;
         }
-        else
+
+        // List item
+        if (line.startsWith("* "))
         {
-            if (line.startsWith("* "))
+            if (current_list == nullptr)
             {
-                if (current_list == nullptr)
-                {
-                    cursor.deletePreviousChar();
-                    cursor.insertBlock();
-                    cursor.setBlockFormat(text_style.standard_format);
-                    current_list = cursor.createList(text_style.list_format);
-                }
-                else
-                {
-                    cursor.insertBlock();
-                }
-
-                replace_quotes(line);
-                QString item = trim_whitespace(line.mid(1));
-
-                cursor.insertText(item, text_style.standard);
-                continue;
+                cursor.deletePreviousChar();
+                cursor.insertBlock();
+                cursor.setBlockFormat(text_style.standard_format);
+                current_list = cursor.createList(text_style.list_format);
             }
             else
             {
-                if (current_list != nullptr)
-                {
-                    cursor.insertBlock();
-                    cursor.setBlockFormat(text_style.standard_format);
-                }
-                current_list = nullptr;
+                cursor.insertBlock();
             }
 
-            if(line.startsWith(">"))
-            {
-                if(!blockquote)
-                {
-                    // Start blockquote
-                    QTextTable *table = cursor.insertTable(1, 1, text_style.blockquote_tableformat);
-                    cursor.setBlockFormat(text_style.blockquote_format);
-                    QTextTableCell cell = table->cellAt(0, 0);
-                    cell.setFormat(text_style.blockquote);
-                    blockquote = true;
-                }
+            replace_quotes(line);
+            insertText(cursor, trim_whitespace(line.mid(1)), text_style.standard);
+            continue;
+        }
 
-                replace_quotes(line);
-                cursor.insertText(trim_whitespace(line.mid(1)) + "\n", text_style.blockquote);
+        // End of list
+        if (current_list != nullptr)
+        {
+            cursor.insertBlock();
+            cursor.setBlockFormat(text_style.standard_format);
+        }
+        current_list = nullptr;
 
-                continue;
-            }
-            else
+        // Block quote
+        if(line.startsWith(">"))
+        {
+            if(!blockquote)
             {
-                if (blockquote)
-                {
-                    // End blockquote
-                    cursor.deletePreviousChar();
-                    cursor.movePosition(QTextCursor::NextBlock);
-                    cursor.setBlockFormat(text_style.standard_format);
-                }
-                blockquote  = false;
+                // Start blockquote
+                QTextTable *table = cursor.insertTable(1, 1, text_style.blockquote_tableformat);
+                cursor.setBlockFormat(text_style.blockquote_format);
+                QTextTableCell cell = table->cellAt(0, 0);
+                cell.setFormat(text_style.blockquote);
+                blockquote = true;
             }
 
-            if (line.startsWith("###"))
-            {
-                auto heading = trim_whitespace(line.mid(3));
+            replace_quotes(line);
+            insertText(cursor, trim_whitespace(line.mid(1)), text_style.blockquote);
+            cursor.insertText("\n", text_style.standard);
+            continue;
+        }
 
-                auto id = unique_anchor_name();
-                auto fmt = text_style.standard_h3;
-                fmt.setAnchor(true);
-                fmt.setAnchorNames(QStringList { id });
+        // End of blockquote
+        if (blockquote)
+        {
+            cursor.deletePreviousChar();
+            cursor.movePosition(QTextCursor::NextBlock);
+            cursor.setBlockFormat(text_style.standard_format);
+        }
+        blockquote = false;
 
-                outline.appendH3(heading, id);
+        // Headings, etc.
+        if (line.startsWith("###"))
+        {
+            auto heading = trim_whitespace(line.mid(3));
 
-                cursor.setBlockFormat(text_style.heading_format);
-                cursor.insertText(replace_quotes(heading), fmt);
-                cursor.insertText("\n", text_style.standard);
-            }
-            else if (line.startsWith("##"))
-            {
-                auto heading = trim_whitespace(line.mid(2));
+            auto id = unique_anchor_name();
+            auto fmt = text_style.standard_h3;
+            fmt.setAnchor(true);
+            fmt.setAnchorNames(QStringList { id });
 
-                auto id = unique_anchor_name();
-                auto fmt = text_style.standard_h2;
-                fmt.setAnchor(true);
-                fmt.setAnchorNames(QStringList { id });
+            outline.appendH3(heading, id);
 
-                outline.appendH2(heading, id);
+            cursor.setBlockFormat(text_style.heading_format);
+            insertText(cursor, replace_quotes(heading), fmt);
+            cursor.insertText("\n", text_style.standard);
+        }
+        else if (line.startsWith("##"))
+        {
+            auto heading = trim_whitespace(line.mid(2));
 
-                cursor.setBlockFormat(text_style.heading_format);
-                cursor.insertText(replace_quotes(heading), fmt);
-                cursor.insertText("\n", text_style.standard);
-            }
-            else if (line.startsWith("#"))
-            {
-                auto heading = trim_whitespace(line.mid(1));
+            auto id = unique_anchor_name();
+            auto fmt = text_style.standard_h2;
+            fmt.setAnchor(true);
+            fmt.setAnchorNames(QStringList { id });
 
-                auto id = unique_anchor_name();
-                auto fmt = text_style.standard_h1;
-                fmt.setAnchor(true);
-                fmt.setAnchorNames(QStringList { id });
+            outline.appendH2(heading, id);
 
-                outline.appendH1(heading, id);
+            cursor.setBlockFormat(text_style.heading_format);
+            insertText(cursor, replace_quotes(heading), fmt);
+            cursor.insertText("\n", text_style.standard);
+        }
+        else if (line.startsWith("#"))
+        {
+            auto heading = trim_whitespace(line.mid(1));
 
-                // Use first heading as the page's title.
-                if (page_title != nullptr && page_title->isEmpty())
-                {
-                    *page_title = heading;
-                }
+            auto id = unique_anchor_name();
+            auto fmt = text_style.standard_h1;
+            fmt.setAnchor(true);
+            fmt.setAnchorNames(QStringList { id });
 
-                // Centre the first heading. We can't use the above code block
-                // for this because it doesn't get run on every re-render of the page
-                if (centre_first_h1)
-                {
-                    auto f = text_style.heading_format;
-                    f.setAlignment(Qt::AlignCenter);
-                    cursor.setBlockFormat(f);
-                    centre_first_h1 = false;
-                }
-                else
-                {
-                    cursor.setBlockFormat(text_style.heading_format);
-                }
+            outline.appendH1(heading, id);
 
-                cursor.insertText(replace_quotes(heading), fmt);
-                cursor.insertText("\n", text_style.standard);
+            // Use first heading as the page's title.
+            if (page_title != nullptr && page_title->isEmpty())
+            {
+                *page_title = heading;
+            }
+
+            // Centre the first heading. We can't use the above code block
+            // for this because it doesn't get run on every re-render of the page
+            if (centre_first_h1)
+            {
+                auto f = text_style.heading_format;
+                f.setAlignment(Qt::AlignCenter);
+                cursor.setBlockFormat(f);
+                centre_first_h1 = false;
             }
-            else if (line.startsWith("=>"))
+            else
             {
-                auto const part = line.mid(2).trimmed();
+                cursor.setBlockFormat(text_style.heading_format);
+            }
 
-                QByteArray link, title;
+            insertText(cursor, replace_quotes(heading), fmt);
+            cursor.insertText("\n", text_style.standard);
+        }
+        else if (line.startsWith("=>"))
+        {
+            auto const part = line.mid(2).trimmed();
 
-                int index = -1;
-                for (int i = 0; i < part.size(); i++)
-                {
-                    if (isspace(part[i]))
-                    {
-                        index = i;
-                        break;
-                    }
-                }
+            QByteArray link, title;
 
-                if (index > 0)
-                {
-                    link = trim_whitespace(part.mid(0, index));
-                    title = trim_whitespace(part.mid(index + 1));
-                }
-                else
+            int index = -1;
+            for (int i = 0; i < part.size(); i++)
+            {
+                if (isspace(part[i]))
                 {
-                    link = trim_whitespace(part);
-                    title = trim_whitespace(part);
+                    index = i;
+                    break;
                 }
-                replace_quotes(title);
-
-                auto local_url = QUrl(link);
+            }
 
-                // Makes relative URLs with scheme provided (e.g gemini:///relative) work
-                // From RFC 1630: "If the scheme parts are different, the whole absolute URI must be given"
-                // therefor the schemes must be same for this to be allowed.
-                if (local_url.scheme() == root_url.scheme() &&
-                    local_url.authority().isEmpty() &&
-                    local_url.scheme() != "about" &&
-                    local_url.scheme() != "file")
-                {
-                    // qDebug() << "Adjusting local url: " << local_url;
-                    local_url = local_url.adjusted(QUrl::RemoveScheme | QUrl::RemoveAuthority);
-                }
-                auto absolute_url = root_url.resolved(local_url);
+            if (index > 0)
+            {
+                link = trim_whitespace(part.mid(0, index));
+                title = trim_whitespace(part.mid(index + 1));
+            }
+            else
+            {
+                link = trim_whitespace(part);
+                title = trim_whitespace(part);
+            }
+            replace_quotes(title);
 
-                // qDebug() << link << title;
+            auto local_url = QUrl(link);
 
-                auto fmt = text_style.standard_link;
+            // Makes relative URLs with scheme provided (e.g gemini:///relative) work
+            // From RFC 1630: "If the scheme parts are different, the whole absolute URI must be given"
+            // therefor the schemes must be same for this to be allowed.
+            if (local_url.scheme() == root_url.scheme() &&
+                local_url.authority().isEmpty() &&
+                local_url.scheme() != "about" &&
+                local_url.scheme() != "file")
+            {
+                // qDebug() << "Adjusting local url: " << local_url;
+                local_url = local_url.adjusted(QUrl::RemoveScheme | QUrl::RemoveAuthority);
+            }
+            auto absolute_url = root_url.resolved(local_url);
 
-                QString prefix;
-                if (absolute_url.host() == root_url.host())
-                {
-                    prefix = themed_style.internal_link_prefix;
-                    fmt = text_style.standard_link;
-                }
-                else
-                {
-                    prefix = themed_style.external_link_prefix;
-                    fmt = text_style.external_link;
-                }
+            // qDebug() << link << title;
 
-                QString suffix = "";
-                if (absolute_url.scheme() != root_url.scheme())
-                {
-                    if(absolute_url.scheme() != "kristall+ctrl") {
-                        suffix = " [" + absolute_url.scheme().toUpper() + "]";
-                        fmt = text_style.cross_protocol_link;
-                    }
-                }
+            auto fmt = text_style.standard_link;
 
-                fmt.setAnchor(true);
-                fmt.setAnchorHref(absolute_url.toString());
-                cursor.setBlockFormat(text_style.link_format);
-                cursor.insertText(prefix + title + suffix + "\n", fmt);
-            }
-            else if (line.startsWith("```"))
+            QString prefix;
+            if (absolute_url.host() == root_url.host())
             {
-                verbatim = true;
+                prefix = themed_style.internal_link_prefix;
+                fmt = text_style.standard_link;
             }
             else
             {
-                cursor.setBlockFormat(text_style.standard_format);
-                replace_quotes(line);
+                prefix = themed_style.external_link_prefix;
+                fmt = text_style.external_link;
+            }
 
-                if(emit_fancy_text)
-                {
-                    // Just render lines not containing asterisks/underscores normally.
-                    // This actually helps reduce the small overhead on large pages to
-                    // being almost negligable
-                    if (!line.contains("*") && !line.contains("_"))
-                    {
-                        cursor.insertText(line + "\n", text_style.standard);
-                        continue;
-                    }
-
-                    // Easier to work on this as an array of QChars
-                    QString text(line);
-
-                    // Whether to hide formatting codes (*, and _). This option
-                    // is mainly here so that the code which strips these is
-                    // more understandable.
-                    static const bool HIDE_FORMATS = true;
-
-                    // The first thing we do is convert double-asterisk bolding to single-asterisk.
-                    // This makes it A LOT easier to bold these things.
-                    //
-                    // This is done using this regex. In a simpler, pseudo form, it can be written as:
-                    // (punctuation/whitespace/line-begin)+\*\*(bolded text)\*\*(punctuation/whitespace/EOL)
-                    // Just stare at it a bit and you might figure out how it works...
-                    QRegularExpression BOLD_DBL_REGEX
-                        = QRegularExpression(R"((^|[\s.,!?[\]()\\-])+\*\*([^\*\s]+[^\*]+[^\*\s]+)\*\*($|[\s.,!?[\]()\\-]))");
-                    text.replace(BOLD_DBL_REGEX,  QString(R"(\1*\2*\3)"));
-
-                    QTextCharFormat fmt = text_style.standard;
-                    bool bold = false, underline = false;
-                    bool was_bold = false, was_underline = false;
-                    int last = 0;
-
-                    // Used to prepare the format before actually drawing the text.
-                    auto format_text = [&bold, &underline, &was_bold, &was_underline, &last, &text, &fmt](int i) -> QString
-                    {
-                        // Makes sure that bold/underline text only gets printed
-                        // if it has a matching * or _.
-                        if (bold && !text.mid(i, text.length() - i).contains("*"))
-                            bold = false;
-                        if (underline && !text.mid(i, text.length() - i).contains("_"))
-                            underline = false;
-
-                        // Sets format to bold/underline as necessary.
-                        auto f = fmt.font();
-                        f.setBold(bold);
-                        fmt.setFont(f);
-                        fmt.setUnderlineStyle(underline ?
-                            QTextCharFormat::SingleUnderline : QTextCharFormat::NoUnderline);
-
-                        // Remove formats
-                        QString span = text.mid(last, i - last);
-                        if (HIDE_FORMATS &&
-                            span.length() > 1 &&
-                            (((bold || was_bold) && span.startsWith("*")) ||
-                             ((underline || was_underline) && span.startsWith("_"))))
-                        {
-                            span = span.mid(1, span.length() - 1);
-                        }
-
-                        return span;
-                    };
-
-                    for (int i = 0; i < text.length(); ++i)
-                    {
-                        if (text[i] == '*')
-                        {
-                            // Format and insert the text.
-                            cursor.insertText(format_text(i), fmt);
-
-                            // 'Toggle' bold state.
-                            if (was_bold) was_bold = false;
-                            if (bold) {
-                                was_bold = true;
-                                bold = false;
-                            } else {
-                                // Only start bold formatting if this looks like bold formatting:
-                                // * Previous char must be either whitespace, nothing
-                                // * Next char must not be: whitespace, comma, full-stop, asterisk, or underscore.
-                                if ((i == 0 || text[i - 1].isSpace()) &&
-                                    (i + 1) < text.length() &&
-                                    !text[i + 1].isSpace() &&
-                                    text[i + 1] != ',' &&
-                                    text[i + 1] != '.' &&
-                                    text[i + 1] != '*' &&
-                                    text[i + 1] != '_')
-                                {
-                                    bold = true;
-                                }
-                            }
-
-                            last = i;
-                        }
-                        else if (text[i] == '_')
-                        {
-                            // Insert the text
-                            cursor.insertText(format_text(i), fmt);
-
-                            // 'Toggle' underline state.
-                            if (was_underline) was_underline = false;
-                            if (underline) {
-                                was_underline = true;
-                                underline = false;
-                            } else {
-                                // Only start underline formatting if it looks like an underline.
-                                // * Previous char must be either whitespace or nothing
-                                // * Next char must not be: whitespace, comma, full-stop, asterisk, or underscore.
-                                if ((i == 0 || text[i - 1].isSpace()) &&
-                                    (i + 1) < text.length() &&
-                                    !text[i + 1].isSpace() &&
-                                    text[i + 1] != ',' &&
-                                    text[i + 1] != '.' &&
-                                    text[i + 1] != '*' &&
-                                    text[i + 1] != '_')
-                                {
-                                    underline = true;
-                                }
-                            }
-
-                            last = i;
-                        }
-
-                        if (i == text.length() - 1)
-                        {
-                            QString span = text.mid(last, i - last + 1);
-
-                            // Skip if the span is just an asterisk/underline
-                            if (HIDE_FORMATS &&
-                                ((was_bold && span == "*") ||
-                                (was_underline && span == "_")))
-                            {
-                                break;
-                            }
-
-                            // Strips previous underline/asterisk
-                            if (HIDE_FORMATS &&
-                                span.length() > 1 &&
-                                ((was_bold && span.startsWith("*")) ||
-                                 (was_underline && span.startsWith("_"))))
-                            {
-                                span = span.mid(1, span.length() - 1);
-                            }
-
-                            // Draw ending text normally.
-                            cursor.insertText(span, text_style.standard);
-                            break;
-                        }
-                    }
-
-                    cursor.insertText("\n", text_style.standard);
-                }
-                else {
-                    cursor.insertText(line + "\n", text_style.standard);
+            QString suffix = "";
+            if (absolute_url.scheme() != root_url.scheme())
+            {
+                if(absolute_url.scheme() != "kristall+ctrl") {
+                    suffix = " [" + absolute_url.scheme().toUpper() + "]";
+                    fmt = text_style.cross_protocol_link;
                 }
             }
+
+            fmt.setAnchor(true);
+            fmt.setAnchorHref(absolute_url.toString());
+            cursor.setBlockFormat(text_style.link_format);
+            insertText(cursor, (prefix + title + suffix).toUtf8(), fmt);
+            cursor.insertText("\n", text_style.standard);
+        }
+        else if (line.startsWith("```"))
+        {
+            verbatim = true;
+        }
+        else
+        {
+            cursor.setBlockFormat(text_style.standard_format);
+
+            replace_quotes(line);
+            insertText(cursor, line, text_style.standard);
+            cursor.insertText("\n", text_style.standard);
         }
     }
 
@@ -537,3 +382,164 @@ static QByteArray replace_quotes(QByteArray &line)
 
     return line;
 }
+
+/*
+ * Handles all the fancy text highlighting.
+ */
+static void insertText(QTextCursor &cursor, const QByteArray &line,
+    const QTextCharFormat &format)
+{
+    if (line.isEmpty() ||
+
+        // Render text normally if text decoration is disabled.
+        !kristall::globals().options.enable_text_decoration ||
+
+        // Render lines not containing asterisks/underscores normally.
+        // This actually helps reduce the small overhead on large pages to
+        // being almost negligable
+        (!line.contains("*") && !line.contains("_")))
+    {
+        // Empty lines must be in standard format.
+        cursor.insertText(line, format);
+        return;
+    }
+
+    // Easier to work on this as an array of QChars
+    QString text(line);
+
+    // Whether to hide formatting codes (*, and _). This option
+    // is mainly here so that the code which strips these is
+    // more understandable.
+    static const bool HIDE_FORMATS = true;
+
+    // The first thing we do is convert double-asterisk bolding to single-asterisk.
+    // This makes it A LOT easier to bold these things.
+    //
+    // This is done using this regex. In a simpler, pseudo form, it can be written as:
+    // (punctuation/whitespace/line-begin)+\*\*(bolded text)\*\*(punctuation/whitespace/EOL)
+    // Just stare at it a bit and you might figure out how it works...
+    QRegularExpression BOLD_DBL_REGEX
+        = QRegularExpression(R"((^|[\s.,!?[\]()\\-])+\*\*([^\*\s]+[^\*]+[^\*\s]+)\*\*($|[\s.,!?[\]()\\-]))");
+    text.replace(BOLD_DBL_REGEX,  QString(R"(\1*\2*\3)"));
+
+    QTextCharFormat fmt = format;
+    bool bold = false, underline = false;
+    bool was_bold = false, was_underline = false;
+    int last = 0;
+
+    // Used to prepare the format before actually drawing the text.
+    auto format_text = [&bold, &underline, &was_bold, &was_underline, &last, &text, &fmt](int i) -> QString
+    {
+        // Makes sure that bold/underline text only gets printed
+        // if it has a matching * or _.
+        if (bold && !text.mid(i, text.length() - i).contains("*"))
+            bold = false;
+        if (underline && !text.mid(i, text.length() - i).contains("_"))
+            underline = false;
+
+        // Sets format to bold/underline as necessary.
+        auto f = fmt.font();
+        f.setBold(bold);
+        fmt.setFont(f);
+        fmt.setUnderlineStyle(underline ?
+            QTextCharFormat::SingleUnderline : QTextCharFormat::NoUnderline);
+
+        // Remove formats
+        QString span = text.mid(last, i - last);
+        if (HIDE_FORMATS &&
+            span.length() > 1 &&
+            (((bold || was_bold) && span.startsWith("*")) ||
+             ((underline || was_underline) && span.startsWith("_"))))
+        {
+            span = span.mid(1, span.length() - 1);
+        }
+
+        return span;
+    };
+
+    for (int i = 0; i < text.length(); ++i)
+    {
+        if (text[i] == '*')
+        {
+            // Format and insert the text.
+            cursor.insertText(format_text(i), fmt);
+
+            // 'Toggle' bold state.
+            if (was_bold) was_bold = false;
+            if (bold) {
+                was_bold = true;
+                bold = false;
+            } else {
+                // Only start bold formatting if this looks like bold formatting:
+                // * Previous char must be either whitespace, nothing
+                // * Next char must not be: whitespace, comma, full-stop, asterisk, or underscore.
+                if ((i == 0 || text[i - 1].isSpace()) &&
+                    (i + 1) < text.length() &&
+                    !text[i + 1].isSpace() &&
+                    text[i + 1] != ',' &&
+                    text[i + 1] != '.' &&
+                    text[i + 1] != '*' &&
+                    text[i + 1] != '_')
+                {
+                    bold = true;
+                }
+            }
+
+            last = i;
+        }
+        else if (text[i] == '_')
+        {
+            // Insert the text
+            cursor.insertText(format_text(i), fmt);
+
+            // 'Toggle' underline state.
+            if (was_underline) was_underline = false;
+            if (underline) {
+                was_underline = true;
+                underline = false;
+            } else {
+                // Only start underline formatting if it looks like an underline.
+                // * Previous char must be either whitespace or nothing
+                // * Next char must not be: whitespace, comma, full-stop, asterisk, or underscore.
+                if ((i == 0 || text[i - 1].isSpace()) &&
+                    (i + 1) < text.length() &&
+                    !text[i + 1].isSpace() &&
+                    text[i + 1] != ',' &&
+                    text[i + 1] != '.' &&
+                    text[i + 1] != '*' &&
+                    text[i + 1] != '_')
+                {
+                    underline = true;
+                }
+            }
+
+            last = i;
+        }
+
+        if (i == text.length() - 1)
+        {
+            QString span = text.mid(last, i - last + 1);
+
+            // Skip if the span is just an asterisk/underline
+            if (HIDE_FORMATS &&
+                ((was_bold && span == "*") ||
+                (was_underline && span == "_")))
+            {
+                break;
+            }
+
+            // Strips previous underline/asterisk
+            if (HIDE_FORMATS &&
+                span.length() > 1 &&
+                ((was_bold && span.startsWith("*")) ||
+                 (was_underline && span.startsWith("_"))))
+            {
+                span = span.mid(1, span.length() - 1);
+            }
+
+            // Draw ending text normally.
+            cursor.insertText(span, format);
+            break;
+        }
+    }
+}