Snap to grid (#3016)

* Add widget to side panel

* Draw grid

* snap tool to grid

* Update french translation

* Format code with clang-format

Co-authored-by: joshua <joshua@qelectrotech.org>

src/widgets/capture/capturewidget.cpp

@@ -393,6 +393,18 @@ void CaptureWidget::xywhTick()
     repaint();
 }
 
+void CaptureWidget::onDisplayGridChanged(bool display)
+{
+    m_displayGrid = display;
+    repaint();
+}
+
+void CaptureWidget::onGridSizeChanged(int size)
+{
+    m_gridSize = size;
+    repaint();
+}
+
 void CaptureWidget::showxywh(bool show)
 {
     int timeout =
@@ -605,6 +617,31 @@ void CaptureWidget::paintEvent(QPaintEvent* paintEvent)
                          xy);
     }
 
+    if (m_displayGrid) {
+        painter.save();
+        QColor uicolor = ConfigHandler().uiColor();
+        uicolor.setAlpha(100);
+        painter.setPen(uicolor);
+        painter.setBrush(QBrush(uicolor));
+
+        auto topLeft = mapToGlobal(m_context.selection.topLeft());
+        topLeft.rx() -= topLeft.x() % m_gridSize;
+        topLeft.ry() -= topLeft.y() % m_gridSize;
+        topLeft = mapFromGlobal(topLeft);
+
+        const auto scale{ m_context.screenshot.devicePixelRatio() };
+        const auto step{ m_gridSize * scale };
+        const auto radius{ 1 * scale };
+
+        for (int y = topLeft.y(); y < m_context.selection.bottom(); y += step) {
+            for (int x = topLeft.x(); x < m_context.selection.right();
+                 x += step) {
+                painter.drawEllipse(x, y, radius, radius);
+            }
+        }
+        painter.restore();
+    }
+
     if (m_activeTool && m_mouseIsClicked) {
         m_activeTool->process(painter, m_context.screenshot);
     } else if (m_previewEnabled && activeButtonTool() &&
@@ -671,7 +708,8 @@ bool CaptureWidget::startDrawObjectTool(const QPoint& pos)
                 &CaptureTool::requestAction,
                 this,
                 &CaptureWidget::handleToolSignal);
-        m_context.mousePos = pos;
+
+        m_context.mousePos = m_displayGrid ? snapToGrid(pos) : pos;
         m_activeTool->drawStart(m_context);
         // TODO this is the wrong place to do this
 
@@ -847,7 +885,8 @@ void CaptureWidget::mouseMoveEvent(QMouseEvent* e)
         if (m_adjustmentButtonPressed) {
             m_activeTool->drawMoveWithAdjustment(e->pos());
         } else {
-            m_activeTool->drawMove(e->pos());
+            m_activeTool->drawMove(m_displayGrid ? snapToGrid(e->pos())
+                                                 : e->pos());
         }
         // update drawing object
         updateTool(m_activeTool);
@@ -1126,6 +1165,14 @@ void CaptureWidget::initPanel()
             &SidePanelWidget::togglePanel,
             m_panel,
             &UtilityPanel::toggle);
+    connect(m_sidePanel,
+            &SidePanelWidget::displayGridChanged,
+            this,
+            &CaptureWidget::onDisplayGridChanged);
+    connect(m_sidePanel,
+            &SidePanelWidget::gridSizeChanged,
+            this,
+            &CaptureWidget::onGridSizeChanged);
     // TODO replace with a CaptureWidget signal
     emit m_sidePanel->colorChanged(m_context.color);
     emit toolSizeChanged(m_context.toolSize);
@@ -1721,6 +1768,20 @@ CaptureTool::Type CaptureWidget::activeButtonToolType() const
     return activeTool->type();
 }
 
+QPoint CaptureWidget::snapToGrid(const QPoint& point) const
+{
+    QPoint snapPoint = mapToGlobal(point);
+
+    const auto scale{ m_context.screenshot.devicePixelRatio() };
+
+    snapPoint.setX((qRound(snapPoint.x() / double(m_gridSize)) * m_gridSize) *
+                   scale);
+    snapPoint.setY((qRound(snapPoint.y() / double(m_gridSize)) * m_gridSize) *
+                   scale);
+
+    return mapFromGlobal(snapPoint);
+}
+
 QPointer<CaptureTool> CaptureWidget::activeToolObject()
 {
     return m_captureToolObjects.at(m_panel->activeLayerIndex());

src/widgets/capture/capturewidget.h

@@ -87,6 +87,8 @@ private slots:
     void onMoveCaptureToolDown(int captureToolIndex);
     void selectAll();
     void xywhTick();
+    void onDisplayGridChanged(bool display);
+    void onGridSizeChanged(int size);
 
 public:
     void removeToolObject(int index = -1);
@@ -147,6 +149,8 @@ private:
     CaptureTool* activeButtonTool() const;
     CaptureTool::Type activeButtonToolType() const;
 
+    QPoint snapToGrid(const QPoint& point) const;
+
     ////////////////////////////////////////
     // Class members
 
@@ -214,4 +218,8 @@ private:
     // For start moving after more than X offset
     QPoint m_startMovePos;
     bool m_startMove;
+
+    // Grid
+    bool m_displayGrid{ false };
+    int m_gridSize{ 10 };
 };

src/widgets/panel/sidepanelwidget.cpp

@@ -8,6 +8,7 @@
 #include "src/utils/pathinfo.h"
 #include "utilitypanel.h"
 #include <QApplication>
+#include <QCheckBox>
 #include <QKeyEvent>
 #include <QLabel>
 #include <QLineEdit>
@@ -80,6 +81,18 @@ SidePanelWidget::SidePanelWidget(QPixmap* p, QWidget* parent)
     m_layout->addWidget(m_colorWheel);
     m_layout->addWidget(m_colorHex);
 
+    QHBoxLayout* gridHBoxLayout = new QHBoxLayout(this);
+    m_gridCheck = new QCheckBox(tr("Display grid"), this);
+    m_gridSizeSpin = new QSpinBox(this);
+    m_gridSizeSpin->setRange(5, 50);
+    m_gridSizeSpin->setSingleStep(5);
+    m_gridSizeSpin->setValue(10);
+    m_gridSizeSpin->setDisabled(true);
+    m_gridSizeSpin->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
+    gridHBoxLayout->addWidget(m_gridCheck);
+    gridHBoxLayout->addWidget(m_gridSizeSpin);
+    m_layout->addLayout(gridHBoxLayout);
+
     // tool size sigslots
     connect(m_toolSizeSpin,
             static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged),
@@ -112,6 +125,15 @@ SidePanelWidget::SidePanelWidget(QPixmap* p, QWidget* parent)
             &color_widgets::ColorWheel::colorSelected,
             this,
             &SidePanelWidget::colorChanged);
+    // Grid feature
+    connect(m_gridCheck, &QCheckBox::clicked, this, [=](bool b) {
+        this->m_gridSizeSpin->setEnabled(b);
+        emit this->displayGridChanged(b);
+    });
+    connect(m_gridSizeSpin,
+            qOverload<int>(&QSpinBox::valueChanged),
+            this,
+            &SidePanelWidget::gridSizeChanged);
 }
 
 void SidePanelWidget::onColorChanged(const QColor& color)

src/widgets/panel/sidepanelwidget.h

@@ -14,6 +14,7 @@ class QLineEdit;
 class ColorGrabWidget;
 class QColorPickingEventFilter;
 class QSlider;
+class QCheckBox;
 
 constexpr int maxToolSize = 50;
 constexpr int minSliderWidth = 100;
@@ -31,6 +32,8 @@ signals:
     void colorChanged(const QColor& color);
     void toolSizeChanged(int size);
     void togglePanel();
+    void displayGridChanged(bool display);
+    void gridSizeChanged(int size);
 
 public slots:
     void onToolSizeChanged(int tool);
@@ -61,4 +64,6 @@ private:
     QSpinBox* m_toolSizeSpin;
     QSlider* m_toolSizeSlider;
     int m_toolSize{};
+    QCheckBox* m_gridCheck{ nullptr };
+    QSpinBox* m_gridSizeSpin{ nullptr };
 };