Add a start for a Qt text editor (mainly for playing around - but it could turn into something useful down the road).

1 files changed, 114 insertions, 0 deletions

diff --git a/desktop-utilities/lumina-textedit/PlainTextEditor.cpp b/desktop-utilities/lumina-textedit/PlainTextEditor.cpp
new file mode 100644
index 00000000..7b105d20
--- /dev/null
+++ b/desktop-utilities/lumina-textedit/PlainTextEditor.cpp
@@ -0,0 +1,114 @@
+//===========================================
+//  Lumina-DE source code
+//  Copyright (c) 2015, Ken Moore
+//  Available under the 3-clause BSD license
+//  See the LICENSE file for full details
+//===========================================
+#include "PlainTextEditor.h"
+
+#include <QColor>
+#include <QPainter>
+#include <QTextBlock>
+
+//==============
+//       PUBLIC
+//==============
+PlainTextEditor::PlainTextEditor(QWidget *parent) : QPlainTextEdit(parent){
+  LNW = new LNWidget(this);
+  showLNW = true;
+  connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(LNW_updateWidth()) );
+  connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(LNW_highlightLine()) );
+  connect(this, SIGNAL(updateRequest(const QRect&, int)), this, SLOT(LNW_update(const QRect&, int)) );
+	
+  LNW_updateWidth();
+  LNW_highlightLine();
+}
+PlainTextEditor::~PlainTextEditor(){
+	
+}
+
+void PlainTextEditor::showLineNumbers(bool show){
+  showLNW = show;
+  LNW->setVisible(show);
+  LNW_updateWidth();
+}
+
+//Functions for managing the line number widget
+int PlainTextEditor::LNWWidth(){
+  //Get the number of chars we need for line numbers
+  int lines = this->blockCount();
+  if(lines<1){ lines = 1; }
+  int chars = 1;
+  while(lines>=10){ chars++; lines/=10; }
+  return (this->fontMetrics().width("9")*chars + 4); //make sure to add a tiny bit of padding
+}
+
+void PlainTextEditor::paintLNW(QPaintEvent *ev){
+  QPainter P(LNW);
+  //First set the background color
+  P.fillRect(ev->rect(), QColor("lightgrey"));
+  //Now determine which line numbers to show (based on the current viewport)
+  QTextBlock block = this->firstVisibleBlock();
+  int bTop = blockBoundingGeometry(block).translated(contentOffset()).top();
+  int bBottom;
+  //Now loop over the blocks (lines) and write in the numbers
+  P.setPen(Qt::black); //setup the font color
+  while(block.isValid() && bTop<=ev->rect().bottom()){ //ensure block below top of viewport
+    bBottom = bTop+blockBoundingRect(block).height();
+    if(block.isVisible() && bBottom >= ev->rect().top()){ //ensure block above bottom of viewport
+      P.drawText(0,bTop, LNW->width(), this->fontMetrics().height(), Qt::AlignRight, QString::number(block.blockNumber()+1) );
+    }
+    //Go to the next block
+    block = block.next();
+    bTop = bBottom;
+  }
+}
+	
+//==============
+//       PRIVATE
+//==============
+
+//===================
+//       PRIVATE SLOTS
+//===================
+//Functions for managing the line number widget
+void PlainTextEditor::LNW_updateWidth(){
+  if(showLNW){
+    this->setViewportMargins( LNWWidth(), 0, 0, 0); //the LNW is contained within the left margin
+  }else{
+    this->setViewportMargins( 0, 0, 0, 0); //the LNW is contained within the left margin
+  }
+}
+
+void PlainTextEditor::LNW_highlightLine(){
+  if(this->isReadOnly()){ return; }
+  QColor highC = QColor(0,0,0,50); //just darken the line a bit
+  QTextEdit::ExtraSelection sel;
+  sel.format.setBackground(highC);
+  sel.format.setProperty(QTextFormat::FullWidthSelection, true);
+  sel.cursor = this->textCursor();
+  sel.cursor.clearSelection(); //just in case it already has one
+  setExtraSelections( QList<QTextEdit::ExtraSelection>() << sel );
+}
+
+void PlainTextEditor::LNW_update(const QRect &rect, int dy){
+  if(dy!=0){ LNW->scroll(0,dy); } //make sure to scroll the line widget the same amount as the editor
+  else{
+    //Some other reason we need to repaint the widget
+    LNW->update(0,rect.y(), LNW->width(), rect.height()); //also repaint the LNW in the same area
+  }
+  if(rect.contains(this->viewport()->rect())){
+    //Something in the currently-viewed area needs updating - make sure the LNW width is still correct
+    LNW_updateWidth();
+  }
+}
+
+//==================
+//       PROTECTED
+//==================
+void PlainTextEditor::resizeEvent(QResizeEvent *ev){
+  QPlainTextEdit::resizeEvent(ev); //do the normal resize processing
+  //Now re-adjust the placement of the LNW (within the left margin area)
+  QRect cGeom = this->contentsRect();
+  LNW->setGeometry( QRect(cGeom.left(), cGeom.top(), LNWWidth(), cGeom.height()) );
+}