Grid painting

gridpreview.cpp

@@ -2,7 +2,11 @@
 
 GridPreview::GridPreview(QWidget *parent)
     : QWidget{parent}
-{}
+{
+    colorMap.insert(QString("red"), Qt::red);
+    colorMap.insert(QString("green"), Qt::green);
+    colorMap.insert(QString("blue"), Qt::blue);
+}
 
 void GridPreview::setSize(int newWidth, int newHeight)
 {
@@ -32,3 +36,74 @@ QString GridPreview::toLuaTable()
     linesSubTable.removeLast(); // ,
     return output.arg(linesSubTable);
 }
+
+void GridPreview::paintEvent(QPaintEvent *event)
+{
+    QPainter painter(this);
+    QPen pen(Qt::black, 2);
+    painter.setPen(pen);
+    QBrush brush(Qt::black);
+    bool widthBased = rect().width() > rect().height();
+    int cellSize = widthBased ?
+                       rect().height() / height :
+                       rect().width() / width;
+
+    int dotSize = cellSize * 0.5;
+    int filledDotSize = cellSize * 0.7;
+
+    int areaWidth = cellSize * width;
+    int areaHeight = cellSize * height;
+
+    int offsetX = (rect().width() - areaWidth) / 2;
+    int offsetY = (rect().height() - areaHeight) / 2;
+
+    QRect drawArea(offsetX, offsetY, areaWidth, areaHeight);
+
+    // Draw main grid
+
+    painter.drawRect(drawArea);
+
+    QRect cell(0, 0, cellSize, cellSize);
+    painter.setBrush(brush);
+    for (int cellX = 0; cellX < width; cellX++)
+    {
+        for (int cellY = 0; cellY < height; cellY++)
+        {
+            cell.setLeft(offsetX + (cellSize - dotSize) / 2 + cellX * cellSize);
+            cell.setWidth(dotSize);
+            cell.setTop(offsetY + (cellSize - dotSize) / 2 + cellY * cellSize);
+            cell.setHeight(dotSize);
+            painter.drawEllipse(cell);
+        }
+    }
+
+    // Draw line points
+
+    for (auto iter = lines.begin(); iter < lines.end(); iter++)
+    {
+        QColor color(colorFromString(iter->getColor()));
+        brush.setColor(color);
+        painter.setBrush(brush);
+
+        // Draw start
+        cell.setLeft(offsetX + (cellSize - filledDotSize) / 2 + (iter->getStartX() - 1) * cellSize);
+        cell.setWidth(filledDotSize);
+        cell.setTop(offsetY + (cellSize - filledDotSize) / 2 + (iter->getStartY() - 1) * cellSize);
+        cell.setHeight(filledDotSize);
+        painter.drawEllipse(cell);
+
+        // Draw end
+        cell.setLeft(offsetX + (cellSize - filledDotSize) / 2 + (iter->getEndX() - 1) * cellSize);
+        cell.setWidth(filledDotSize);
+        cell.setTop(offsetY + (cellSize - filledDotSize) / 2 + (iter->getEndY() - 1) * cellSize);
+        cell.setHeight(filledDotSize);
+        painter.drawEllipse(cell);
+    }
+}
+
+QColor GridPreview::colorFromString(QString color)
+{
+    if (!colorMap.contains(color))
+        return colorMap[QString("red")];
+    return colorMap[color];
+}

gridpreview.h

@@ -2,6 +2,7 @@
 #define GRIDPREVIEW_H
 
 #include <QWidget>
+#include <QPainter>
 #include "line.h"
 
 class GridPreview : public QWidget
@@ -13,9 +14,12 @@ public:
     void addLine(Line &line);
     void removeLine(int index);
     QString toLuaTable();
+    void paintEvent(QPaintEvent* event);
+    QColor colorFromString(QString color);
 private:
     int width = 5, height = 5;
     QVector<Line> lines {};
+    QMap<QString, QColor> colorMap;
     const QString tableTemplate = "return {\n    width = %1,\n    height = %2,\n    lines = {\n%3\n    }\n}";
 signals:
 };

mainwindow.ui

@@ -96,7 +96,11 @@
          <number>6</number>
         </property>
         <item>
-         <widget class="QPlainTextEdit" name="textPreview"/>
+         <widget class="QPlainTextEdit" name="textPreview">
+          <property name="readOnly">
+           <bool>true</bool>
+          </property>
+         </widget>
         </item>
         <item>
          <layout class="QHBoxLayout" name="layoutButtons">
@@ -395,6 +399,13 @@
             </property>
            </widget>
           </item>
+          <item>
+           <widget class="QPushButton" name="buttonDeleteLine">
+            <property name="text">
+             <string>Delete selected line</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </item>
        </layout>