api/is-window-visible: move from header

1 files changed, 33 insertions, 0 deletions

diff --git a/opentrack/is-window-visible.cpp b/opentrack/is-window-visible.cpp
new file mode 100644
index 00000000..fc25bb7d
--- /dev/null
+++ b/opentrack/is-window-visible.cpp
@@ -0,0 +1,33 @@
+#include "is-window-visible.hpp"
+#include <QPoint>
+
+#ifdef _WIN32
+
+#include <windows.h>
+
+OPENTRACK_API_EXPORT bool is_window_visible(const QWidget* widget)
+{
+    const QPoint p = widget->mapToGlobal(QPoint(0, 0));
+    const QSize s = widget->size();
+
+    const POINT points[] =
+    {
+        { p.x(), p.y() },
+        { p.x() + s.width(), p.y() },
+        { p.x() + s.width(), p.y() + s.height() },
+        { p.x(), p.y() + s.height() },
+        { p.x() + s.width()/2, p.y() + s.height()/2 },
+    };
+
+    for (const POINT& pt : points)
+        if (WindowFromPoint(pt) == (HWND) widget->winId())
+            return true;
+    return false;
+}
+
+#else
+OPENTRACK_API_EXPORT bool is_window_visible(const QWidget* widget)
+{
+    return true;
+}
+#endif