richtextdialog: implemented basic html tag editing

Another step in moving away from the WYSIWYG rich text dialog.
2020-07-11 01:44:48 +10:00
parent 39d71eb7cd
commit ceeb491293
2 changed files with 225 additions and 25 deletions
@@ -20,6 +20,7 @@

 #include "richtext.h"

+#include <QDebug>
 #include <QDialogButtonBox>
 #include <QHBoxLayout>
 #include <QPushButton>
@@ -37,13 +38,13 @@ RichTextDialog::RichTextDialog(QString start, QWidget* parent) :
  // Create toolbar
  QHBoxLayout* toolbar_layout = new QHBoxLayout();

-  bold_btn_ = CreateToolbarButton(tr("B"), tr("Bold"));
+  bold_btn_ = CreateToolbarButton(tr("B"), tr("Bold"), {QStringLiteral("b"), QStringLiteral("strong")});
  toolbar_layout->addWidget(bold_btn_);
-  italic_btn_ = CreateToolbarButton(tr("I"), tr("Italic"));
+  italic_btn_ = CreateToolbarButton(tr("I"), tr("Italic"), {QStringLiteral("i"), QStringLiteral("em")});
  toolbar_layout->addWidget(italic_btn_);
-  underline_btn_ = CreateToolbarButton(tr("U"), tr("Underline"));
+  underline_btn_ = CreateToolbarButton(tr("U"), tr("Underline"), {QStringLiteral("u")});
  toolbar_layout->addWidget(underline_btn_);
-  strikeout_btn_ = CreateToolbarButton(tr("S"), tr("Strikethrough"));
+  strikeout_btn_ = CreateToolbarButton(tr("S"), tr("Strikethrough"), {QStringLiteral("strike")});
  toolbar_layout->addWidget(strikeout_btn_);
  font_combo_ = new QFontComboBox();
  font_combo_->setToolTip(tr("Font Family"));
@@ -56,13 +57,13 @@ RichTextDialog::RichTextDialog(QString start, QWidget* parent) :

  toolbar_layout->addStretch();

-  left_align_btn_ = CreateToolbarButton(tr("L"), tr("Left Align"));
+  left_align_btn_ = CreateToolbarButton(tr("L"), tr("Left Align"), {});
  toolbar_layout->addWidget(left_align_btn_);
-  center_align_btn_ = CreateToolbarButton(tr("C"), tr("Center Align"));
+  center_align_btn_ = CreateToolbarButton(tr("C"), tr("Center Align"), {});
  toolbar_layout->addWidget(center_align_btn_);
-  right_align_btn_ = CreateToolbarButton(tr("R"), tr("Right Align"));
+  right_align_btn_ = CreateToolbarButton(tr("R"), tr("Right Align"), {});
  toolbar_layout->addWidget(right_align_btn_);
-  justify_align_btn_ = CreateToolbarButton(tr("J"), tr("Justify Align"));
+  justify_align_btn_ = CreateToolbarButton(tr("J"), tr("Justify Align"), {});
  toolbar_layout->addWidget(justify_align_btn_);

  layout->addLayout(toolbar_layout);
@@ -70,7 +71,7 @@ RichTextDialog::RichTextDialog(QString start, QWidget* parent) :
  // Create text edit widget
  text_edit_ = new QTextEdit();
  text_edit_->setWordWrapMode(QTextOption::NoWrap);
-  //connect(text_edit_, &QTextEdit::cursorPositionChanged, this, &RichTextDialog::UpdateButtons);
+  connect(text_edit_, &QTextEdit::cursorPositionChanged, this, &RichTextDialog::UpdateButtons);
  start.replace(QStringLiteral("<br>"), QStringLiteral("\n"));
  text_edit_->document()->setPlainText(start);
  layout->addWidget(text_edit_);
@@ -83,16 +84,6 @@ RichTextDialog::RichTextDialog(QString start, QWidget* parent) :

  // Connect font buttons
  /*
-  connect(bold_btn_, &QPushButton::clicked, this, [this](bool e){
-    text_edit_->setFontWeight(e ? QFont::Bold : QFont::Normal);
-  });
-  connect(italic_btn_, &QPushButton::clicked, text_edit_, &QTextEdit::setFontItalic);
-  connect(underline_btn_, &QPushButton::clicked, text_edit_, &QTextEdit::setFontUnderline);
-  connect(strikeout_btn_, &QPushButton::clicked, this, [this](bool e){
-    QFont current_font = text_edit_->currentFont();
-    current_font.setStrikeOut(e);
-    text_edit_->setCurrentFont(current_font);
-  });
  connect(size_slider_, &FloatSlider::ValueChanged, text_edit_, &QTextEdit::setFontPointSize);
  connect(left_align_btn_, &QPushButton::clicked, this, [this](){
    text_edit_->setAlignment(Qt::AlignLeft);
@@ -118,22 +109,218 @@ RichTextDialog::RichTextDialog(QString start, QWidget* parent) :
  */
 }

-QPushButton *RichTextDialog::CreateToolbarButton(const QString& label, const QString& tooltip)
+QPushButton *RichTextDialog::CreateToolbarButton(const QString& label, const QString& tooltip, const QStringList &tags)
 {
  QPushButton* btn = new QPushButton(label);
  btn->setCheckable(true);
  btn->setToolTip(tooltip);
  btn->setFixedWidth(btn->sizeHint().height());
+
+  if (!tags.isEmpty()) {
+    btn->setProperty("tag", tags);
+    connect(btn, &QPushButton::clicked, this, &RichTextDialog::TagButtonToggled);
+  }
+
  return btn;
 }

+int SnapPositionOutsideTags(const QString& text, int pos)
+{
+  // Look for closest opening bracket before position
+  int opening_bracket_pos = text.lastIndexOf('<', pos - text.size() -1);
+
+  // Look for closest closing bracket before position
+  int closing_bracket_pos = text.indexOf('>', opening_bracket_pos);
+
+  if (opening_bracket_pos > -1 && closing_bracket_pos >= pos) {
+    // Must be inside an angle bracket, snap to closest position outside of bracket
+    closing_bracket_pos++;
+
+    if (pos - opening_bracket_pos < closing_bracket_pos - pos) {
+      // Closer to opening bracket pos
+      return opening_bracket_pos;
+    } else {
+      return closing_bracket_pos;
+    }
+  }
+
+  return pos;
+}
+
+void RichTextDialog::SetTags(const QStringList &t, bool enabled)
+{
+  QString s = text_edit_->toPlainText();
+
+  int selection_start, selection_end;
+
+  {
+    QTextCursor c = text_edit_->textCursor();
+
+    if (c.hasSelection()) {
+      selection_start = SnapPositionOutsideTags(s, c.selectionStart());
+      selection_end = SnapPositionOutsideTags(s, c.selectionEnd());
+
+      c.clearSelection();
+      c.setPosition(selection_start, QTextCursor::MoveAnchor);
+      c.setPosition(selection_end, QTextCursor::KeepAnchor);
+    } else {
+      selection_start = SnapPositionOutsideTags(s, c.position());
+      selection_end = selection_start;
+      c.setPosition(selection_start, QTextCursor::MoveAnchor);
+    }
+
+    text_edit_->setTextCursor(c);
+  }
+
+  QString open_tag = CreateOpeningTag(t.first());
+  QString close_tag = CreateClosingTag(t.first());
+
+  // Insert tags
+  QString new_text;
+
+  if (!enabled) {
+    std::swap(open_tag, close_tag);
+  }
+
+  bool open_tag_cancels_out = !QString::compare(s.mid(selection_start - close_tag.size(), close_tag.size()), close_tag, Qt::CaseInsensitive);
+  bool close_tag_cancels_out = !QString::compare(s.mid(selection_end, open_tag.size()), open_tag, Qt::CaseInsensitive);
+
+  QString selected_text = text_edit_->textCursor().selectedText();
+
+  if (open_tag_cancels_out && close_tag_cancels_out) {
+
+    // Both tags cancel each other out, simply remove
+    selection_start -= close_tag.size();
+
+    QTextCursor c = text_edit_->textCursor();
+    c.clearSelection();
+    c.setPosition(selection_start, QTextCursor::MoveAnchor);
+    c.setPosition(selection_end + open_tag.size(), QTextCursor::KeepAnchor);
+    text_edit_->setTextCursor(c);
+
+    selection_end -= close_tag.size();
+
+    new_text = selected_text;
+
+  } else if (open_tag_cancels_out) {
+
+    // Open tag cancels out, shift close tag rather than inserting new tags
+    selection_start -= close_tag.size();
+
+    QTextCursor c = text_edit_->textCursor();
+    c.clearSelection();
+    c.setPosition(selection_start, QTextCursor::MoveAnchor);
+    c.setPosition(selection_end, QTextCursor::KeepAnchor);
+    text_edit_->setTextCursor(c);
+
+    selection_end -= close_tag.size();
+
+    new_text = selected_text;
+    new_text.append(close_tag);
+
+  } else if (close_tag_cancels_out) {
+
+    // Close tag cancels out, shift open tag rather than inserting new tags
+    selection_end += open_tag.size();
+
+    QTextCursor c = text_edit_->textCursor();
+    c.clearSelection();
+    c.setPosition(selection_start, QTextCursor::MoveAnchor);
+    c.setPosition(selection_end, QTextCursor::KeepAnchor);
+    text_edit_->setTextCursor(c);
+
+    selection_start += open_tag.size();
+
+    new_text = open_tag;
+    new_text.append(selected_text);
+
+  } else {
+    // Nothing is cancelled out, simply insert tags
+    new_text = QStringLiteral("%1%2%3").arg(open_tag,
+                                            selected_text,
+                                            close_tag);
+
+    selection_start += open_tag.size();
+    selection_end += open_tag.size();
+  }
+
+  text_edit_->insertPlainText(new_text);
+
+  text_edit_->setFocus();
+
+  {
+    // Re-select text
+    QTextCursor c = text_edit_->textCursor();
+
+    c.clearSelection();
+    c.setPosition(selection_start, QTextCursor::MoveAnchor);
+    c.setPosition(selection_end, QTextCursor::KeepAnchor);
+    text_edit_->setTextCursor(c);
+  }
+}
+
+QString RichTextDialog::CreateOpeningTag(const QString &s)
+{
+  return QStringLiteral("<%1>").arg(s);
+}
+
+QString RichTextDialog::CreateClosingTag(const QString &s)
+{
+  return QStringLiteral("</%1>").arg(s);
+}
+
+void RichTextDialog::UpdateTagButton(QPushButton *btn,
+                                     const QString &text,
+                                     int cursor_pos)
+{
+  QStringList tags = btn->property("tag").toStringList();
+  foreach (const QString& t, tags) {
+    QString opening = CreateOpeningTag(t);
+    QString closing = CreateClosingTag(t);
+
+    int opening_index = text.lastIndexOf(opening,
+                                         cursor_pos - text.size() - 1,
+                                         Qt::CaseInsensitive);
+    int closing_index = text.indexOf(closing,
+                                     opening_index,
+                                     Qt::CaseInsensitive);
+
+    if (opening_index > -1 && closing_index + closing.size() > cursor_pos) {
+      btn->setChecked(true);
+      btn->setProperty("foundtag", t);
+      return;
+    }
+  }
+
+  btn->setChecked(false);
+  btn->setProperty("foundtag", QVariant());
+}
+
+void RichTextDialog::TagButtonToggled(bool checked)
+{
+  QPushButton* src = static_cast<QPushButton*>(sender());
+  QStringList tags;
+
+  if (src->property("foundtag").isNull()) {
+    tags = src->property("tag").toStringList();
+  } else {
+    tags = QStringList({src->property("foundtag").toString()});
+  }
+
+  SetTags(tags, checked);
+}
+
 void RichTextDialog::UpdateButtons()
 {
+  QString text = text_edit_->toPlainText();
+  int cursor_pos = text_edit_->textCursor().position();
+
+  UpdateTagButton(bold_btn_, text, cursor_pos);
+  UpdateTagButton(italic_btn_, text, cursor_pos);
+  UpdateTagButton(underline_btn_, text, cursor_pos);
+  UpdateTagButton(strikeout_btn_, text, cursor_pos);
+
  /*
-  bold_btn_->setChecked(text_edit_->fontWeight() > QFont::Normal);
-  italic_btn_->setChecked(text_edit_->fontItalic());
-  underline_btn_->setChecked(text_edit_->fontUnderline());
-  strikeout_btn_->setChecked(text_edit_->currentFont().strikeOut());

  // Update font family
  font_combo_->blockSignals(true);
@@ -47,7 +47,18 @@ public:
  }

 private:
-  QPushButton* CreateToolbarButton(const QString &label, const QString &tooltip);
+  QPushButton* CreateToolbarButton(const QString &label,
+                                   const QString &tooltip,
+                                   const QStringList& tags);
+
+  void SetTags(const QStringList& t, bool enabled);
+
+  static QString CreateOpeningTag(const QString& s);
+  static QString CreateClosingTag(const QString& s);
+
+  static void UpdateTagButton(QPushButton* btn,
+                              const QString &text,
+                              int cursor_pos);

  QFontDatabase font_db_;

@@ -65,6 +76,8 @@ private:
  QPushButton* justify_align_btn_;

 private slots:
+  void TagButtonToggled(bool checked);
+
  void UpdateButtons();

 };