editor: auto format table

.gitignore

@@ -1 +1 @@
-/VNote.pro.user
+VNote.pro.user

README_zh.md

@@ -1,5 +1,5 @@
 # VNote
-- [英文 English](./README.md)
+[英文 English](./README.md)
 
 **VNote是一个更懂程序员和Markdown的笔记！**
 

src/markdownhighlighterdata.h

@@ -121,6 +121,40 @@ struct VMathjaxBlock
 };
 
 
+struct VTableBlock
+{
+    VTableBlock()
+        : m_startPos(-1),
+          m_endPos(-1)
+    {
+    }
+
+    bool isValid() const
+    {
+        return m_startPos > -1 && m_endPos >= m_startPos;
+    }
+
+    void clear()
+    {
+        m_startPos = m_endPos = -1;
+        m_borders.clear();
+    }
+
+    QString toString() const
+    {
+        return QString("table [%1,%2) borders %3").arg(m_startPos)
+                                                  .arg(m_endPos)
+                                                  .arg(m_borders.size());
+    }
+
+    int m_startPos;
+    int m_endPos;
+
+    // Global position of the table borders in ascending order.
+    QVector<int> m_borders;
+};
+
+
 // Highlight unit with global position and string style name.
 struct HLUnitPos
 {
@@ -157,6 +191,11 @@ struct VElementRegion
         return m_startPos <= p_pos && m_endPos > p_pos;
     }
 
+    bool contains(const VElementRegion &p_reg) const
+    {
+        return m_startPos <= p_reg.m_startPos && m_endPos >= p_reg.m_endPos;
+    }
+
     bool intersect(int p_start, int p_end) const
     {
         return !(p_end <= m_startPos || p_start >= m_endPos);

src/peghighlighterresult.cpp

@@ -51,6 +51,8 @@ PegHighlighterResult::PegHighlighterResult(const PegMarkdownHighlighter *p_peg,
     parseMathjaxBlocks(p_peg, p_result);
 
     parseHRuleBlocks(p_peg, p_result);
+
+    parseTableBlocks(p_peg, p_result);
 }
 
 static bool compHLUnit(const HLUnit &p_a, const HLUnit &p_b)
@@ -270,6 +272,66 @@ void PegHighlighterResult::parseFencedCodeBlocks(const PegMarkdownHighlighter *p
     }
 }
 
+void PegHighlighterResult::parseTableBlocks(const PegMarkdownHighlighter *p_peg,
+                                            const QSharedPointer<PegParseResult> &p_result)
+{
+    const QVector<VElementRegion> &tableRegs = p_result->m_tableRegions;
+    const QVector<VElementRegion> &headerRegs = p_result->m_tableHeaderRegions;
+    const QVector<VElementRegion> &borderRegs = p_result->m_tableBorderRegions;
+
+    VTableBlock item;
+    int headerIdx = 0, borderIdx = 0;
+    for (int tableIdx = 0; tableIdx < tableRegs.size(); ++tableIdx) {
+        const auto &reg = tableRegs[tableIdx];
+        if (headerIdx < headerRegs.size()) {
+            if (reg.contains(headerRegs[headerIdx])) {
+                // A new table.
+                if (item.isValid()) {
+                    // Save previous table.
+                    m_tableBlocks.append(item);
+
+                    auto &table = m_tableBlocks.back();
+                    // Fill borders.
+                    for (; borderIdx < borderRegs.size(); ++borderIdx) {
+                        if (borderRegs[borderIdx].m_startPos >= table.m_startPos
+                            && borderRegs[borderIdx].m_endPos <= table.m_endPos) {
+                            table.m_borders.append(borderRegs[borderIdx].m_startPos);
+                        } else {
+                            break;
+                        }
+                    }
+                }
+
+                item.clear();
+                item.m_startPos = reg.m_startPos;
+                item.m_endPos = reg.m_endPos;
+
+                ++headerIdx;
+                continue;
+            }
+        }
+
+        // Continue previous table.
+        item.m_endPos = reg.m_endPos;
+    }
+
+    if (item.isValid()) {
+        // Another table.
+        m_tableBlocks.append(item);
+
+        // Fill borders.
+        auto &table = m_tableBlocks.back();
+        for (; borderIdx < borderRegs.size(); ++borderIdx) {
+            if (borderRegs[borderIdx].m_startPos >= table.m_startPos
+                && borderRegs[borderIdx].m_endPos <= table.m_endPos) {
+                table.m_borders.append(borderRegs[borderIdx].m_startPos);
+            } else {
+                break;
+            }
+        }
+    }
+}
+
 static inline bool isDisplayFormulaRawEnd(const QString &p_text)
 {
     QRegExp regex("\\\\end\\{[^{}\\s\\r\\n]+\\}$");
@@ -330,8 +392,8 @@ void PegHighlighterResult::parseMathjaxBlocks(const PegMarkdownHighlighter *p_pe
                 break;
             }
 
-            int pib = r.m_startPos - block.position();
-            int length = r.m_endPos - r.m_startPos;
+            int pib = qMax(r.m_startPos - block.position(), 0);
+            int length = qMin(r.m_endPos - block.position() - pib, block.length() - 1);
             QString text = block.text().mid(pib, length);
             if (inBlock) {
                 item.m_text = item.m_text + "\n" + text;

src/peghighlighterresult.h

@@ -88,6 +88,10 @@ public:
 
     QSet<int> m_hruleBlocks;
 
+    // All table blocks.
+    // Sorted by start position ascendingly.
+    QVector<VTableBlock> m_tableBlocks;
+
 private:
     // Parse highlight elements for blocks from one parse result.
     static void parseBlocksHighlightOne(QVector<QVector<HLUnit>> &p_blocksHighlights,
@@ -108,6 +112,10 @@ private:
     void parseHRuleBlocks(const PegMarkdownHighlighter *p_peg,
                           const QSharedPointer<PegParseResult> &p_result);
 
+    // Parse table blocks from parse results.
+    void parseTableBlocks(const PegMarkdownHighlighter *p_peg,
+                          const QSharedPointer<PegParseResult> &p_result);
+
 #if 0
     void parseBlocksElementRegionOne(QHash<int, QVector<VElementRegion>> &p_regs,
                                      const QTextDocument *p_doc,

src/pegmarkdownhighlighter.cpp

@@ -203,7 +203,7 @@ static bool containSpecialChar(const QString &p_str)
     QChar la = p_str[p_str.size() - 1];
 
     return fi == '#'
-           || la == '`' || la == '$' || la == '*' || la == '_';
+           || la == '`' || la == '$' || la == '~' || la == '*' || la == '_';
 }
 
 bool PegMarkdownHighlighter::preHighlightSingleFormatBlock(const QVector<QVector<HLUnit>> &p_highlights,
@@ -757,6 +757,8 @@ void PegMarkdownHighlighter::completeHighlight(QSharedPointer<PegHighlighterResu
         emit mathjaxBlocksUpdated(p_result->m_mathjaxBlocks);
     }
 
+    emit tableBlocksUpdated(p_result->m_tableBlocks);
+
     emit imageLinksUpdated(p_result->m_imageRegions);
     emit headersUpdated(p_result->m_headerRegions);
 }

src/pegmarkdownhighlighter.h

@@ -70,6 +70,9 @@ signals:
     // Emitted when Mathjax blocks updated.
     void mathjaxBlocksUpdated(const QVector<VMathjaxBlock> &p_mathjaxBlocks);
 
+    // Emitted when table blocks updated.
+    void tableBlocksUpdated(const QVector<VTableBlock> &p_tableBlocks);
+
 protected:
     void highlightBlock(const QString &p_text) Q_DECL_OVERRIDE;
 

src/pegparser.cpp

@@ -25,30 +25,20 @@ void PegParseResult::parse(QAtomicInt &p_stop, bool p_fast)
     parseDisplayFormulaRegions(p_stop);
 
     parseHRuleRegions(p_stop);
+
+    parseTableRegions(p_stop);
+
+    parseTableHeaderRegions(p_stop);
+
+    parseTableBorderRegions(p_stop);
 }
 
 void PegParseResult::parseImageRegions(QAtomicInt &p_stop)
 {
-    // From Qt5.7, the capacity is preserved.
-    m_imageRegions.clear();
-    if (isEmpty()) {
-        return;
-    }
-
-    pmh_element *elem = m_pmhElements[pmh_IMAGE];
-    while (elem != NULL) {
-        if (elem->end <= elem->pos) {
-            elem = elem->next;
-            continue;
-        }
-
-        if (p_stop.load() == 1) {
-            return;
-        }
-
-        m_imageRegions.push_back(VElementRegion(m_offset + elem->pos, m_offset + elem->end));
-        elem = elem->next;
-    }
+    parseRegions(p_stop,
+                 pmh_IMAGE,
+                 m_imageRegions,
+                 false);
 }
 
 void PegParseResult::parseHeaderRegions(QAtomicInt &p_stop)
@@ -113,64 +103,63 @@ void PegParseResult::parseFencedCodeBlockRegions(QAtomicInt &p_stop)
 
 void PegParseResult::parseInlineEquationRegions(QAtomicInt &p_stop)
 {
-    m_inlineEquationRegions.clear();
-    if (isEmpty()) {
-        return;
-    }
-
-    pmh_element *elem = m_pmhElements[pmh_INLINEEQUATION];
-    while (elem != NULL) {
-        if (elem->end <= elem->pos) {
-            elem = elem->next;
-            continue;
-        }
-
-        if (p_stop.load() == 1) {
-            return;
-        }
-
-        m_inlineEquationRegions.push_back(VElementRegion(m_offset + elem->pos, m_offset + elem->end));
-        elem = elem->next;
-    }
+    parseRegions(p_stop,
+                 pmh_INLINEEQUATION,
+                 m_inlineEquationRegions,
+                 false);
 }
 
 void PegParseResult::parseDisplayFormulaRegions(QAtomicInt &p_stop)
 {
-    m_displayFormulaRegions.clear();
-    if (isEmpty()) {
-        return;
-    }
-
-    pmh_element *elem = m_pmhElements[pmh_DISPLAYFORMULA];
-    while (elem != NULL) {
-        if (elem->end <= elem->pos) {
-            elem = elem->next;
-            continue;
-        }
-
-        if (p_stop.load() == 1) {
-            return;
-        }
-
-        m_displayFormulaRegions.push_back(VElementRegion(m_offset + elem->pos, m_offset + elem->end));
-        elem = elem->next;
-    }
-
-    if (p_stop.load() == 1) {
-        return;
-    }
-
-    std::sort(m_displayFormulaRegions.begin(), m_displayFormulaRegions.end());
+    parseRegions(p_stop,
+                 pmh_DISPLAYFORMULA,
+                 m_displayFormulaRegions,
+                 true);
 }
 
 void PegParseResult::parseHRuleRegions(QAtomicInt &p_stop)
 {
-    m_hruleRegions.clear();
+    parseRegions(p_stop,
+                 pmh_HRULE,
+                 m_hruleRegions,
+                 false);
+}
+
+void PegParseResult::parseTableRegions(QAtomicInt &p_stop)
+{
+    parseRegions(p_stop,
+                 pmh_TABLE,
+                 m_tableRegions,
+                 true);
+}
+
+void PegParseResult::parseTableHeaderRegions(QAtomicInt &p_stop)
+{
+    parseRegions(p_stop,
+                 pmh_TABLEHEADER,
+                 m_tableHeaderRegions,
+                 true);
+}
+
+void PegParseResult::parseTableBorderRegions(QAtomicInt &p_stop)
+{
+    parseRegions(p_stop,
+                 pmh_TABLEBORDER,
+                 m_tableBorderRegions,
+                 true);
+}
+
+void PegParseResult::parseRegions(QAtomicInt &p_stop,
+                                  pmh_element_type p_type,
+                                  QVector<VElementRegion> &p_result,
+                                  bool p_sort)
+{
+    p_result.clear();
     if (isEmpty()) {
         return;
     }
 
-    pmh_element *elem = m_pmhElements[pmh_HRULE];
+    pmh_element *elem = m_pmhElements[p_type];
     while (elem != NULL) {
         if (elem->end <= elem->pos) {
             elem = elem->next;
@@ -181,9 +170,13 @@ void PegParseResult::parseHRuleRegions(QAtomicInt &p_stop)
             return;
         }
 
-        m_hruleRegions.push_back(VElementRegion(m_offset + elem->pos, m_offset + elem->end));
+        p_result.push_back(VElementRegion(m_offset + elem->pos, m_offset + elem->end));
         elem = elem->next;
     }
+
+    if (p_sort && p_stop.load() != 1) {
+        std::sort(p_result.begin(), p_result.end());
+    }
 }
 
 

src/pegparser.h

@@ -114,6 +114,16 @@ struct PegParseResult
     // HRule regions.
     QVector<VElementRegion> m_hruleRegions;
 
+    // All table regions.
+    // Sorted by start position.
+    QVector<VElementRegion> m_tableRegions;
+
+    // All table header regions.
+    QVector<VElementRegion> m_tableHeaderRegions;
+
+    // All table border regions.
+    QVector<VElementRegion> m_tableBorderRegions;
+
 private:
     void parseImageRegions(QAtomicInt &p_stop);
 
@@ -126,6 +136,17 @@ private:
     void parseDisplayFormulaRegions(QAtomicInt &p_stop);
 
     void parseHRuleRegions(QAtomicInt &p_stop);
+
+    void parseTableRegions(QAtomicInt &p_stop);
+
+    void parseTableHeaderRegions(QAtomicInt &p_stop);
+
+    void parseTableBorderRegions(QAtomicInt &p_stop);
+
+    void parseRegions(QAtomicInt &p_stop,
+                      pmh_element_type p_type,
+                      QVector<VElementRegion> &p_result,
+                      bool p_sort = false);
 };
 
 class PegParserWorker : public QThread

src/resources/themes/v_detorte/v_detorte.css

@@ -143,6 +143,7 @@ hr {
 
 table {
    padding: 0;
+   margin: 1rem 0.5rem;
    border-collapse: collapse;
 }
 

src/resources/themes/v_moonlight/v_moonlight.css

@@ -141,6 +141,7 @@ hr {
 
 table {
    padding: 0;
+   margin: 1rem 0.5rem;
    border-collapse: collapse;
 }
 

src/resources/themes/v_native/v_native.css

@@ -136,6 +136,7 @@ hr {
 
 table {
    padding: 0;
+   margin: 1rem 0.5rem;
    border-collapse: collapse;
 }
 

src/resources/themes/v_pure/v_pure.css

@@ -138,6 +138,7 @@ hr {
 
 table {
    padding: 0;
+   margin: 1rem 0.5rem;
    border-collapse: collapse;
 }
 

src/src.pro

@@ -19,6 +19,13 @@ ICON = resources/icons/vnote.icns
 
 TRANSLATIONS += translations/vnote_zh_CN.ts
 
+*-g++ {
+    QMAKE_CFLAGS_WARN_ON += -Wno-class-memaccess
+    QMAKE_CXXFLAGS_WARN_ON += -Wno-class-memaccess
+    QMAKE_CFLAGS += -Wno-class-memaccess
+    QMAKE_CXXFLAGS += -Wno-class-memaccess
+}
+
 SOURCES += main.cpp\
     vmainwindow.cpp \
     vdirectorytree.cpp \
@@ -150,7 +157,9 @@ SOURCES += main.cpp\
     utils/vkeyboardlayoutmanager.cpp \
     dialog/vkeyboardlayoutmappingdialog.cpp \
     vfilelistwidget.cpp \
-    widgets/vcombobox.cpp
+    widgets/vcombobox.cpp \
+    vtablehelper.cpp \
+    vtable.cpp
 
 HEADERS  += vmainwindow.h \
     vdirectorytree.h \
@@ -293,7 +302,9 @@ HEADERS  += vmainwindow.h \
     utils/vkeyboardlayoutmanager.h \
     dialog/vkeyboardlayoutmappingdialog.h \
     vfilelistwidget.h \
-    widgets/vcombobox.h
+    widgets/vcombobox.h \
+    vtablehelper.h \
+    vtable.h
 
 RESOURCES += \
     vnote.qrc \

src/veditor.h

@@ -213,6 +213,7 @@ public:
     virtual bool findW(const QRegExp &p_exp,
                        QTextDocument::FindFlags p_options = QTextDocument::FindFlags()) = 0;
 
+    virtual bool isReadOnlyW() const = 0;
     virtual void setReadOnlyW(bool p_ro) = 0;
 
     virtual QWidget *viewportW() const = 0;

src/vmainwindow.cpp

@@ -820,7 +820,7 @@ void VMainWindow::initHelpMenu()
     docAct->setToolTip(tr("View VNote's documentation"));
     connect(docAct, &QAction::triggered,
             this, []() {
-                QString url("http://vnote.readthedocs.io");
+                QString url("https://tamlok.github.io/vnote");
                 QDesktopServices::openUrl(url);
             });
 
@@ -828,7 +828,7 @@ void VMainWindow::initHelpMenu()
     donateAct->setToolTip(tr("Donate to VNote or view the donate list"));
     connect(donateAct, &QAction::triggered,
             this, []() {
-                QString url("https://github.com/tamlok/vnote#donate");
+                QString url("https://tamlok.github.io/vnote/en_us/#!donate.md");
                 QDesktopServices::openUrl(url);
             });
 

src/vmdeditor.cpp

@@ -32,6 +32,7 @@
 #include "vgraphvizhelper.h"
 #include "vmdtab.h"
 #include "vdownloader.h"
+#include "vtablehelper.h"
 
 extern VWebUtils *g_webUtils;
 
@@ -109,6 +110,10 @@ VMdEditor::VMdEditor(VFile *p_file,
     connect(m_previewMgr, &VPreviewManager::requestUpdateImageLinks,
             m_pegHighlighter, &PegMarkdownHighlighter::updateHighlight);
 
+    m_tableHelper = new VTableHelper(this);
+    connect(m_pegHighlighter, &PegMarkdownHighlighter::tableBlocksUpdated,
+            m_tableHelper, &VTableHelper::updateTableBlocks);
+
     m_editOps = new VMdEditOperations(this, m_file);
     connect(m_editOps, &VEditOperations::statusMessage,
             m_object, &VEditorObject::statusMessage);
@@ -1446,7 +1451,8 @@ void VMdEditor::initLinkAndPreviewMenu(QAction *p_before, QMenu *p_menu, const Q
     if (regExp.indexIn(text) > -1) {
         const QVector<VElementRegion> &imgRegs = m_pegHighlighter->getImageRegions();
         for (auto const & reg : imgRegs) {
-            if (!reg.contains(pos)) {
+            if (!reg.contains(pos)
+                && (!reg.contains(pos - 1) || pos != (block.position() + text.size()))) {
                 continue;
             }
 
@@ -1608,7 +1614,8 @@ bool VMdEditor::initInPlacePreviewMenu(QAction *p_before,
     int pib = p_pos - p_block.position();
     for (auto info : previews) {
         const VPreviewedImageInfo &pii = info->m_imageInfo;
-        if (pii.contains(pib)) {
+        if (pii.contains(pib)
+            || (pii.contains(pib - 1) && pib == p_block.length() - 1)) {
             const QPixmap *img = findImage(pii.m_imageName);
             if (img) {
                 image = *img;

src/vmdeditor.h

@@ -22,6 +22,7 @@ class VDocument;
 class VPreviewManager;
 class VCopyTextAsHtmlDialog;
 class VEditTab;
+class VTableHelper;
 
 class VMdEditor : public VTextEdit, public VEditor
 {
@@ -152,6 +153,11 @@ public:
         return find(p_exp, p_options);
     }
 
+    bool isReadOnlyW() const Q_DECL_OVERRIDE
+    {
+        return isReadOnly();
+    }
+
     void setReadOnlyW(bool p_ro) Q_DECL_OVERRIDE
     {
         setReadOnly(p_ro);
@@ -325,6 +331,8 @@ private:
 
     VPreviewManager *m_previewMgr;
 
+    VTableHelper *m_tableHelper;
+
     // Image links inserted while editing.
     QVector<ImageLink> m_insertedImages;
 

src/vtable.cpp

@@ -0,0 +1,585 @@
+#include "vtable.h"
+
+#include <QTextDocument>
+#include <QTextLayout>
+
+#include "veditor.h"
+
+const QString VTable::c_defaultDelimiter = "---";
+
+enum { HeaderRowIndex = 0, DelimiterRowIndex = 1 };
+
+VTable::VTable(VEditor *p_editor, const VTableBlock &p_block)
+    : m_editor(p_editor)
+{
+    parseFromTableBlock(p_block);
+}
+
+bool VTable::isValid() const
+{
+    return header() && header()->isValid()
+           && delimiter() && delimiter()->isValid();
+}
+
+void VTable::parseFromTableBlock(const VTableBlock &p_block)
+{
+    clear();
+
+    QTextDocument *doc = m_editor->documentW();
+
+    QTextBlock block = doc->findBlock(p_block.m_startPos);
+    if (!block.isValid()) {
+        return;
+    }
+
+    int lastBlockNumber = doc->findBlock(p_block.m_endPos - 1).blockNumber();
+    if (lastBlockNumber == -1) {
+        return;
+    }
+
+    const QVector<int> &borders = p_block.m_borders;
+    if (borders.isEmpty()) {
+        return;
+    }
+
+    int numRows = lastBlockNumber - block.blockNumber() + 1;
+    if (numRows <= DelimiterRowIndex) {
+        return;
+    }
+
+    calculateBasicWidths(block, borders[0]);
+
+    int borderIdx = 0;
+    m_rows.reserve(numRows);
+    for (int i = 0; i < numRows; ++i) {
+        m_rows.append(Row());
+        if (!parseOneRow(block, borders, borderIdx, m_rows.last())) {
+            clear();
+            return;
+        }
+
+        block = block.next();
+    }
+}
+
+bool VTable::parseOneRow(const QTextBlock &p_block,
+                         const QVector<int> &p_borders,
+                         int &p_borderIdx,
+                         Row &p_row) const
+{
+    if (!p_block.isValid() || p_borderIdx >= p_borders.size()) {
+        return false;
+    }
+
+    p_row.m_block = p_block;
+
+    QString text = p_block.text();
+    int startPos = p_block.position();
+    int endPos = startPos + text.length();
+
+    if (p_borders[p_borderIdx] < startPos
+        || p_borders[p_borderIdx] >= endPos) {
+        return false;
+    }
+
+    for (; p_borderIdx < p_borders.size(); ++p_borderIdx) {
+        int border = p_borders[p_borderIdx];
+        if (border >= endPos) {
+            break;
+        }
+
+        int offset = border - startPos;
+        if (text[offset] != '|') {
+            return false;
+        }
+
+        int nextIdx = p_borderIdx + 1;
+        if (nextIdx >= p_borders.size() || p_borders[nextIdx] >= endPos) {
+            // The last border of this row.
+            ++p_borderIdx;
+            break;
+        }
+
+        int nextOffset = p_borders[nextIdx] - startPos;
+        if (text[nextOffset] != '|') {
+            return false;
+        }
+
+        // Got one cell.
+        Cell cell;
+        cell.m_offset = offset;
+        cell.m_length = nextOffset - offset;
+        cell.m_text = text.mid(cell.m_offset, cell.m_length);
+
+        p_row.m_cells.append(cell);
+    }
+
+    return true;
+}
+
+void VTable::clear()
+{
+    m_rows.clear();
+    m_spaceWidth = 0;
+    m_minusWidth = 0;
+    m_colonWidth = 0;
+    m_defaultDelimiterWidth = 0;
+}
+
+void VTable::format()
+{
+    if (!isValid()) {
+        return;
+    }
+
+    QTextCursor cursor = m_editor->textCursorW();
+    int curRowIdx = cursor.blockNumber() - m_rows[0].m_block.blockNumber();
+    int curPib = -1;
+    if (curRowIdx < 0 || curRowIdx >= m_rows.size()) {
+        curRowIdx = -1;
+    } else {
+        curPib = cursor.positionInBlock();
+    }
+
+    int nrCols = calculateColumnCount();
+    for (int i = 0; i < nrCols; ++i) {
+        formatOneColumn(i, curRowIdx, curPib);
+    }
+}
+
+int VTable::calculateColumnCount() const
+{
+    int nr = 0;
+
+    // Find the longest row.
+    for (const auto & row : m_rows) {
+        if (row.m_cells.size() > nr) {
+            nr = row.m_cells.size();
+        }
+    }
+
+    return nr;
+}
+
+VTable::Row *VTable::header() const
+{
+    if (m_rows.size() <= HeaderRowIndex) {
+        return NULL;
+    }
+
+    return const_cast<VTable::Row *>(&m_rows[HeaderRowIndex]);
+}
+
+VTable::Row *VTable::delimiter() const
+{
+    if (m_rows.size() <= DelimiterRowIndex) {
+        return NULL;
+    }
+
+    return const_cast<VTable::Row *>(&m_rows[DelimiterRowIndex]);
+}
+
+void VTable::formatOneColumn(int p_idx, int p_cursorRowIdx, int p_cursorPib)
+{
+    QVector<CellInfo> cells;
+    int targetWidth = 0;
+    fetchCellInfoOfColumn(p_idx, cells, targetWidth);
+
+    // Get the alignment of this column.
+    const VTable::Alignment align = getColumnAlignment(p_idx);
+
+    // Calculate the formatted text of each cell.
+    for (int rowIdx = 0; rowIdx < cells.size(); ++rowIdx) {
+        auto & info = cells[rowIdx];
+        auto & row = m_rows[rowIdx];
+        if (row.m_cells.size() <= p_idx) {
+            row.m_cells.resize(p_idx + 1);
+        }
+        auto & cell = row.m_cells[p_idx];
+        Q_ASSERT(cell.m_formattedText.isEmpty());
+        Q_ASSERT(cell.m_cursorCoreOffset == -1);
+
+        // Record the cursor position.
+        if (rowIdx == p_cursorRowIdx) {
+            if (cell.m_offset <= p_cursorPib && cell.m_offset + cell.m_length > p_cursorPib) {
+                // Cursor in this cell.
+                int offset = p_cursorPib - cell.m_offset;
+                offset = offset - info.m_coreOffset;
+                if (offset > info.m_coreLength) {
+                    offset = info.m_coreLength;
+                } else if (offset < 0) {
+                    offset = 0;
+                }
+
+                cell.m_cursorCoreOffset = offset;
+            }
+        }
+
+        if (isDelimiterRow(rowIdx)) {
+            if (!isDelimiterCellWellFormatted(cell, info, targetWidth)) {
+                QString core;
+                // Round to 1 when above 0.5 approximately.
+                int delta = m_minusWidth / 2;
+                switch (align) {
+                case Alignment::None:
+                    core = QString((targetWidth + delta) / m_minusWidth, '-');
+                    break;
+
+                case Alignment::Left:
+                    core = ":";
+                    core += QString((targetWidth - m_colonWidth + delta) / m_minusWidth, '-');
+                    break;
+
+                case Alignment::Center:
+                    core = ":";
+                    core += QString((targetWidth - 2 * m_colonWidth + delta) / m_minusWidth, '-');
+                    core += ":";
+                    break;
+
+                case Alignment::Right:
+                    core = QString((targetWidth - m_colonWidth + delta) / m_minusWidth, '-');
+                    core += ":";
+                    break;
+
+                default:
+                    Q_ASSERT(false);
+                    break;
+                }
+
+                Alignment fakeAlign = align == Alignment::None ? Alignment::Left : align;
+                cell.m_formattedText = generateFormattedText(core,
+                                                             0,
+                                                             fakeAlign);
+            }
+        } else {
+            Alignment fakeAlign = align;
+            if (fakeAlign == Alignment::None) {
+                // For Alignment::None, we make the header align center while
+                // content cells align left.
+                if (isHeaderRow(rowIdx)) {
+                    fakeAlign = Alignment::Center;
+                } else {
+                    fakeAlign = Alignment::Left;
+                }
+            }
+
+            if (!isCellWellFormatted(row, cell, info, targetWidth, fakeAlign)) {
+                QString core = cell.m_text.mid(info.m_coreOffset, info.m_coreLength);
+                int nr = (targetWidth - info.m_coreWidth + m_spaceWidth / 2) / m_spaceWidth;
+                cell.m_formattedText = generateFormattedText(core, nr, fakeAlign);
+            }
+        }
+    }
+}
+
+void VTable::fetchCellInfoOfColumn(int p_idx,
+                                   QVector<CellInfo> &p_cellsInfo,
+                                   int &p_targetWidth) const
+{
+    p_targetWidth = m_defaultDelimiterWidth;
+    p_cellsInfo.resize(m_rows.size());
+
+    // Fetch the trimmed core content and its width.
+    for (int i = 0; i < m_rows.size(); ++i) {
+        auto & row = m_rows[i];
+        auto & info = p_cellsInfo[i];
+
+        if (row.m_cells.size() <= p_idx) {
+            // Need to add a new cell later.
+            continue;
+        }
+
+        // Get the info of this cell.
+        const auto & cell = row.m_cells[p_idx];
+        int first = 1, last = cell.m_length - 2;
+        for (; first <= last; ++first) {
+            if (cell.m_text[first] != ' ') {
+                // Found the core content.
+                info.m_coreOffset = first;
+                break;
+            }
+        }
+
+        if (first > last) {
+            // Empty cell.
+            continue;
+        }
+
+        for (; last >= first; --last) {
+            if (cell.m_text[last] != ' ') {
+                // Found the last of core content.
+                info.m_coreLength = last - first + 1;
+                break;
+            }
+        }
+
+        // Calculate the core width.
+        info.m_coreWidth = calculateTextWidth(row.m_block,
+                                              cell.m_offset + info.m_coreOffset,
+                                              info.m_coreLength);
+        // Delimiter row's width should not be considered.
+        if (info.m_coreWidth > p_targetWidth && !isDelimiterRow(i)) {
+            p_targetWidth = info.m_coreWidth;
+        }
+    }
+}
+
+void VTable::calculateBasicWidths(const QTextBlock &p_block, int p_borderPos)
+{
+    QFont font;
+
+    int pib = p_borderPos - p_block.position();
+    QVector<QTextLayout::FormatRange> fmts = p_block.layout()->formats();
+    for (const auto & fmt : fmts) {
+        if (fmt.start <= pib && fmt.start + fmt.length > pib) {
+            // Hit.
+            if (!fmt.format.fontFamily().isEmpty()) {
+                font = fmt.format.font();
+                break;
+            }
+        }
+    }
+
+    QFontMetrics fm(font);
+    m_spaceWidth = fm.width(' ');
+    m_minusWidth = fm.width('-');
+    m_colonWidth = fm.width(':');
+    m_defaultDelimiterWidth = fm.width(c_defaultDelimiter);
+}
+
+int VTable::calculateTextWidth(const QTextBlock &p_block, int p_pib, int p_length) const
+{
+    QTextLine line = p_block.layout()->lineForTextPosition(p_pib);
+    if (line.isValid()) {
+        return line.cursorToX(p_pib + p_length) - line.cursorToX(p_pib);
+    }
+
+    return -1;
+}
+
+bool VTable::isHeaderRow(int p_idx) const
+{
+    return p_idx == HeaderRowIndex;
+}
+
+bool VTable::isDelimiterRow(int p_idx) const
+{
+    return p_idx == DelimiterRowIndex;
+}
+
+QString VTable::generateFormattedText(const QString &p_core,
+                                      int p_nrSpaces,
+                                      Alignment p_align) const
+{
+    Q_ASSERT(p_align != Alignment::None);
+
+    // Align left.
+    int leftSpaces = 0;
+    int rightSpaces = p_nrSpaces;
+
+    if (p_align == Alignment::Center) {
+        leftSpaces = p_nrSpaces / 2;
+        rightSpaces = p_nrSpaces - leftSpaces;
+    } else if (p_align == Alignment::Right) {
+        leftSpaces = p_nrSpaces;
+        rightSpaces = 0;
+    }
+
+    return QString("| %1%2%3 ").arg(QString(leftSpaces, ' '))
+                               .arg(p_core)
+                               .arg(QString(rightSpaces, ' '));
+}
+
+VTable::Alignment VTable::getColumnAlignment(int p_idx) const
+{
+    Row *row = delimiter();
+    if (row->m_cells.size() <= p_idx) {
+        return Alignment::None;
+    }
+
+    QString core = row->m_cells[p_idx].m_text.mid(1).trimmed();
+    Q_ASSERT(!core.isEmpty());
+    bool leftColon = core[0] == ':';
+    bool rightColon = core[core.size() - 1] == ':';
+    if (leftColon) {
+        if (rightColon) {
+            return Alignment::Center;
+        } else {
+            return Alignment::Left;
+        }
+    } else {
+        if (rightColon) {
+            return Alignment::Right;
+        } else {
+            return Alignment::None;
+        }
+    }
+}
+
+static inline bool equalWidth(int p_a, int p_b, int p_margin = 5)
+{
+    return qAbs(p_a - p_b) < p_margin;
+}
+
+bool VTable::isDelimiterCellWellFormatted(const Cell &p_cell,
+                                          const CellInfo &p_info,
+                                          int p_targetWidth) const
+{
+    // We could use core width here for delimiter cell.
+    if (!equalWidth(p_info.m_coreWidth, p_targetWidth, m_minusWidth)) {
+        return false;
+    }
+
+    const QString &text = p_cell.m_text;
+    if (text.size() < 4) {
+        return false;
+    }
+
+    if (text[1] != ' ' || text[text.size() - 1] != ' ') {
+        return false;
+    }
+
+    if (text[2] == ' ' || text[text.size() - 2] == ' ') {
+        return false;
+    }
+
+    return true;
+}
+
+bool VTable::isCellWellFormatted(const Row &p_row,
+                                 const Cell &p_cell,
+                                 const CellInfo &p_info,
+                                 int p_targetWidth,
+                                 VTable::Alignment p_align) const
+{
+    Q_ASSERT(p_align != Alignment::None);
+
+    const QString &text = p_cell.m_text;
+    if (text.size() < 4) {
+        return false;
+    }
+
+    if (text[1] != ' ' || text[text.size() - 1] != ' ') {
+        return false;
+    }
+
+    // Skip alignment check of empty cell.
+    if (p_info.m_coreOffset > 0) {
+        int leftSpaces = p_info.m_coreOffset - 2;
+        int rightSpaces = text.size() - p_info.m_coreOffset - p_info.m_coreLength - 1;
+        switch (p_align) {
+        case Alignment::Left:
+            if (leftSpaces > 0) {
+                return false;
+            }
+
+            break;
+
+        case Alignment::Center:
+            if (qAbs(leftSpaces - rightSpaces) > 1) {
+                return false;
+            }
+
+            break;
+
+        case Alignment::Right:
+            if (rightSpaces > 0) {
+                return false;
+            }
+
+            break;
+
+        default:
+            Q_ASSERT(false);
+            break;
+        }
+    }
+
+    // Calculate the width of the text without two spaces around.
+    int cellWidth = calculateTextWidth(p_row.m_block,
+                                       p_cell.m_offset + 2,
+                                       p_cell.m_length - 3);
+    if (!equalWidth(cellWidth, p_targetWidth, m_spaceWidth)) {
+        return false;
+    }
+
+    return true;
+}
+
+void VTable::write()
+{
+    bool changed = false;
+    QTextCursor cursor = m_editor->textCursorW();
+    int cursorBlock = -1, cursorPib = -1;
+
+    // Write the table row by row.
+    for (auto & row : m_rows) {
+        bool needChange = false;
+        for (const auto & cell : row.m_cells) {
+            if (!cell.m_formattedText.isEmpty()) {
+                needChange = true;
+                break;
+            }
+        }
+
+        if (!needChange) {
+            continue;
+        }
+
+        if (!changed) {
+            changed = true;
+            cursorBlock = cursor.blockNumber();
+            cursorPib = cursor.positionInBlock();
+
+            cursor.beginEditBlock();
+        }
+
+        // Construct the block text.
+        QString newBlockText;
+        int firstOffset = row.m_cells.first().m_offset;
+        if (firstOffset > 0) {
+            // Get the prefix text.
+            QString text = row.m_block.text();
+            newBlockText = text.left(firstOffset);
+        }
+
+        for (auto & cell : row.m_cells) {
+            int pos = newBlockText.size();
+            if (cell.m_formattedText.isEmpty()) {
+                newBlockText += cell.m_text;
+            } else {
+                newBlockText += cell.m_formattedText;
+            }
+
+            if (cell.m_cursorCoreOffset > -1) {
+                // Cursor in this cell.
+                cursorPib = pos + cell.m_cursorCoreOffset + 2;
+                if (cursorPib >= newBlockText.size()) {
+                    cursorPib = newBlockText.size() - 1;
+                }
+            }
+        }
+
+        newBlockText += "|";
+
+        // Replace the whole block.
+        cursor.setPosition(row.m_block.position());
+        cursor.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
+        cursor.insertText(newBlockText);
+    }
+
+    if (changed) {
+        qDebug() << "write formatted table with cursor block" << cursorBlock;
+        cursor.endEditBlock();
+        m_editor->setTextCursorW(cursor);
+
+        // Restore the cursor.
+        QTextBlock block = m_editor->documentW()->findBlockByNumber(cursorBlock);
+        if (block.isValid()) {
+            int pos = block.position() + cursorPib;
+            QTextCursor cur = m_editor->textCursorW();
+            cur.setPosition(pos);
+            m_editor->setTextCursorW(cur);
+        }
+    }
+}

src/vtable.h

@@ -0,0 +1,181 @@
+#ifndef VTABLE_H
+#define VTABLE_H
+
+#include <QTextBlock>
+
+#include "markdownhighlighterdata.h"
+
+class VEditor;
+
+class VTable
+{
+public:
+    struct Cell
+    {
+        Cell()
+            : m_offset(-1),
+              m_length(0),
+              m_cursorCoreOffset(-1)
+        {
+        }
+
+        void clear()
+        {
+            m_offset = -1;
+            m_length = 0;
+            m_text.clear();
+            m_formattedText.clear();
+            m_cursorCoreOffset = -1;
+        }
+
+        // Start offset within block, including the starting border |.
+        int m_offset;
+
+        // Length of this cell, till next border |.
+        int m_length;
+
+        // Text like "|  vnote  ".
+        QString m_text;
+
+        // Formatted text, such as "|   vnote   ".
+        // It is empty if it does not need formatted.
+        QString m_formattedText;
+
+        // If cursor is within this cell, this will not be -1.
+        int m_cursorCoreOffset;
+    };
+
+    struct Row
+    {
+        Row()
+        {
+        }
+
+        bool isValid() const
+        {
+            return m_block.isValid();
+        }
+
+        void clear()
+        {
+            m_block = QTextBlock();
+            m_cells.clear();
+        }
+
+        QString toString() const
+        {
+            QString cells;
+            for (auto & cell : m_cells) {
+                cells += QString(" (%1, %2 [%3])").arg(cell.m_offset)
+                                                 .arg(cell.m_length)
+                                                 .arg(cell.m_text);
+            }
+
+            return QString("row %1 %2").arg(m_block.blockNumber()).arg(cells);
+        }
+
+        QTextBlock m_block;
+        QVector<Cell> m_cells;
+    };
+
+    enum Alignment
+    {
+        None,
+        Left,
+        Center,
+        Right
+    };
+
+    VTable(VEditor *p_editor, const VTableBlock &p_block);
+
+    bool isValid() const;
+
+    void format();
+
+    // Write a formatted table.
+    void write();
+
+    VTable::Row *header() const;
+
+    VTable::Row *delimiter() const;
+
+private:
+    // Used to hold info about a cell when formatting a column.
+    struct CellInfo
+    {
+        CellInfo()
+            : m_coreOffset(0),
+              m_coreLength(0),
+              m_coreWidth(0)
+        {
+        }
+
+        // The offset of the core content within the cell.
+        // Will be 0 if it is an empty cell.
+        int m_coreOffset;
+
+        // The length of the core content.
+        // Will be 0 if it is an empty cell.
+        int m_coreLength;
+
+        // Pixel width of the core content.
+        int m_coreWidth;
+    };
+
+    void parseFromTableBlock(const VTableBlock &p_block);
+
+    void clear();
+
+    bool parseOneRow(const QTextBlock &p_block,
+                     const QVector<int> &p_borders,
+                     int &p_borderIdx,
+                     Row &p_row) const;
+
+    int calculateColumnCount() const;
+
+    // When called with i, the (i - 1) column must have been formatted.
+    void formatOneColumn(int p_idx, int p_cursorRowIdx, int p_cursorPib);
+
+    void fetchCellInfoOfColumn(int p_idx,
+                              QVector<CellInfo> &p_cellsInfo,
+                              int &p_targetWidth) const;
+
+    void calculateBasicWidths(const QTextBlock &p_block, int p_borderPos);
+
+    int calculateTextWidth(const QTextBlock &p_block, int p_pib, int p_length) const;
+
+    bool isHeaderRow(int p_idx) const;
+
+    bool isDelimiterRow(int p_idx) const;
+
+    // @p_nrSpaces: number of spaces to fill core content.
+    QString generateFormattedText(const QString &p_core,
+                                  int p_nrSpaces = 0,
+                                  Alignment p_align = Alignment::Left) const;
+
+    VTable::Alignment getColumnAlignment(int p_idx) const;
+
+    bool isDelimiterCellWellFormatted(const Cell &p_cell,
+                                      const CellInfo &p_info,
+                                      int p_targetWidth) const;
+
+    bool isCellWellFormatted(const Row &p_row,
+                             const Cell &p_cell,
+                             const CellInfo &p_info,
+                             int p_targetWidth,
+                             VTable::Alignment p_align) const;
+
+    VEditor *m_editor;
+
+    // Header, delimiter, and body.
+    QVector<Row> m_rows;
+
+    int m_spaceWidth;
+    int m_minusWidth;
+    int m_colonWidth;
+    int m_defaultDelimiterWidth;
+
+    static const QString c_defaultDelimiter;
+};
+
+#endif // VTABLE_H

src/vtablehelper.cpp

@@ -0,0 +1,54 @@
+#include "vtablehelper.h"
+
+#include "veditor.h"
+#include "vtable.h"
+
+VTableHelper::VTableHelper(VEditor *p_editor, QObject *p_parent)
+    : QObject(p_parent),
+      m_editor(p_editor)
+{
+}
+
+void VTableHelper::updateTableBlocks(const QVector<VTableBlock> &p_blocks)
+{
+    if (m_editor->isReadOnlyW() || !m_editor->isModified()) {
+        return;
+    }
+
+    int idx = currentCursorTableBlock(p_blocks);
+    if (idx == -1) {
+        return;
+    }
+
+    VTable table(m_editor, p_blocks[idx]);
+    if (!table.isValid()) {
+        return;
+    }
+
+    table.format();
+
+    table.write();
+}
+
+int VTableHelper::currentCursorTableBlock(const QVector<VTableBlock> &p_blocks) const
+{
+    // Binary search.
+    int curPos = m_editor->textCursorW().position();
+
+    int first = 0, last = p_blocks.size() - 1;
+    while (first <= last) {
+        int mid = (first + last) / 2;
+        const VTableBlock &block = p_blocks[mid];
+        if (block.m_startPos <= curPos && block.m_endPos >= curPos) {
+            return mid;
+        }
+
+        if (block.m_startPos > curPos) {
+            last = mid - 1;
+        } else {
+            first = mid + 1;
+        }
+    }
+
+    return -1;
+}

src/vtablehelper.h

@@ -0,0 +1,26 @@
+#ifndef VTABLEHELPER_H
+#define VTABLEHELPER_H
+
+#include <QObject>
+
+#include "markdownhighlighterdata.h"
+
+class VEditor;
+
+class VTableHelper : public QObject
+{
+    Q_OBJECT
+public:
+    explicit VTableHelper(VEditor *p_editor, QObject *p_parent = nullptr);
+
+public slots:
+    void updateTableBlocks(const QVector<VTableBlock> &p_blocks);
+
+private:
+    // Return the block index which contains the cursor.
+    int currentCursorTableBlock(const QVector<VTableBlock> &p_blocks) const;
+
+    VEditor *m_editor;
+};
+
+#endif // VTABLEHELPER_H

src/vtextblockdata.h

@@ -75,7 +75,7 @@ struct VPreviewedImageInfo
 
     QString toString() const
     {
-        return QString("previewed image (%1): [%2, %3] padding %4 inline %5 (%6,%7) bg(%8)")
+        return QString("previewed image (%1): [%2, %3) padding %4 inline %5 (%6,%7) bg(%8)")
                       .arg(m_imageName)
                       .arg(m_startPos)
                       .arg(m_endPos)