Реализация scalling-а

Canvas.cpp

@@ -49,6 +49,26 @@ void Canvas::changeMode(Mode _mode)
     mode = _mode;
 }
 
+void Canvas::zoomIn()
+{
+    scaleFactor += ZOOM_STEP;
+    update();
+}
+
+void Canvas::zoomOut()
+{
+    scaleFactor -= ZOOM_STEP;
+    if (scaleFactor < 0.1) // Минимальный масштаб 10%
+        scaleFactor = 0.1;
+    update();
+}
+
+void Canvas::zoomReset()
+{
+    scaleFactor = 1.0;
+    update();
+}
+
 // ===================================================================
 // Методы поиска и проверки
 // ===================================================================
@@ -567,7 +587,7 @@ void Canvas::paintEvent(QPaintEvent* event)
     QPainter p(this);
     p.setRenderHint(QPainter::Antialiasing, true);
     p.translate(width() / 2.0, height() / 2.0);
-    p.scale(1.0, -1.0);
+    p.scale(scaleFactor, -scaleFactor);
 
     p.setPen(Qt::red);
     p.drawLine(-5, 0, 5, 0);
@@ -680,7 +700,14 @@ void Canvas::keyPressEvent(QKeyEvent* event)
         }
         break;
     }
+    
+    case Qt::Key_Plus:
+        zoomIn();
+        break;
 
+    case Qt::Key_Minus:
+        zoomOut();
+        break;
     default:
         QWidget::keyPressEvent(event);
     }
@@ -717,7 +744,8 @@ QPointF Canvas::screenToLogical(const QPointF& screenPos) const
     logical.rx() -= width() / 2.0;
     logical.ry() -= height() / 2.0;
 
-    logical.ry() = -logical.ry();
+    logical.rx() /= scaleFactor;
+    logical.ry() /= -scaleFactor;
 
     return logical;
 }