Magnifier: Add ability to drag the location when it is locked

2 files changed, 32 insertions, 0 deletions

diff --git a/Userland/Applications/Magnifier/MagnifierWidget.cpp b/Userland/Applications/Magnifier/MagnifierWidget.cpp
index e5b77ea225..3c9c669708 100644
--- a/Userland/Applications/Magnifier/MagnifierWidget.cpp
+++ b/Userland/Applications/Magnifier/MagnifierWidget.cpp
@@ -156,3 +156,29 @@ void MagnifierWidget::second_paint_event(GUI::PaintEvent&)
 
     m_color_filter->apply(*target, rect, *clone, rect);
 }
+
+void MagnifierWidget::mousemove_event(GUI::MouseEvent& event)
+{
+    if (m_locked_location.has_value() && m_currently_dragging && !m_pause_capture) {
+        auto current_position = event.position();
+        auto difference = current_position - m_last_drag_position;
+        Gfx::IntPoint remainder = { difference.x() % m_scale_factor, difference.y() % m_scale_factor };
+        auto moved_by = difference / m_scale_factor;
+        m_locked_location = m_locked_location.value() - moved_by;
+        m_last_drag_position = current_position - remainder;
+    }
+}
+
+void MagnifierWidget::mousedown_event(GUI::MouseEvent& event)
+{
+    if (event.button() == GUI::MouseButton::Primary && !m_pause_capture) {
+        m_currently_dragging = true;
+        m_last_drag_position = event.position();
+    }
+}
+
+void MagnifierWidget::mouseup_event(GUI::MouseEvent& event)
+{
+    if (event.button() == GUI::MouseButton::Primary)
+        m_currently_dragging = false;
+}
diff --git a/Userland/Applications/Magnifier/MagnifierWidget.h b/Userland/Applications/Magnifier/MagnifierWidget.h
index 0e9e2400ba..99a1d757d5 100644
--- a/Userland/Applications/Magnifier/MagnifierWidget.h
+++ b/Userland/Applications/Magnifier/MagnifierWidget.h
@@ -47,6 +47,10 @@ private:
     virtual void paint_event(GUI::PaintEvent&) override;
     virtual void second_paint_event(GUI::PaintEvent&) override;
 
+    virtual void mousemove_event(GUI::MouseEvent&) override;
+    virtual void mousedown_event(GUI::MouseEvent&) override;
+    virtual void mouseup_event(GUI::MouseEvent&) override;
+
     void sync();
 
     int m_scale_factor { 2 };
@@ -55,6 +59,8 @@ private:
     CircularQueue<RefPtr<Gfx::Bitmap>, 512> m_grabbed_bitmaps {};
     ssize_t m_frame_offset_from_head { 0 };
     bool m_pause_capture { false };
+    bool m_currently_dragging { false };
+    Gfx::IntPoint m_last_drag_position {};
     Optional<Gfx::IntPoint> m_locked_location {};
     bool m_show_grid { false };
     Gfx::Color m_grid_color { 255, 0, 255, 100 };