add a color picker dialog to palette editor

include/ui/colorpicker.h

@@ -0,0 +1,33 @@
+#ifndef COLORPICKER_H
+#define COLORPICKER_H
+
+#include <QDialog>
+#include <QGraphicsScene>
+
+namespace Ui {
+class ColorPicker;
+}
+
+class ColorPicker : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit ColorPicker(QWidget *parent = nullptr);
+    ~ColorPicker();
+
+    QColor getColor() { return this->color; }
+
+private:
+    Ui::ColorPicker *ui;
+    QGraphicsScene *scene = nullptr;
+    QTimer *timer = nullptr;
+
+    QPoint lastCursorPos = QPoint(0, 0);
+
+    QColor color = Qt::white;
+
+    void hover(int mouseX, int mouseY);
+};
+
+#endif // COLORPICKER_H

include/ui/paletteeditor.h

@@ -34,6 +34,7 @@ private:
     QList<QList<QSlider*>> sliders;
     QList<QFrame*> frames;
     QList<QLabel*> rgbLabels;
+    QList<QToolButton *> pickButtons;
     Tileset *primaryTileset;
     Tileset *secondaryTileset;
     QList<History<PaletteHistoryItem*>> palettesHistory;
@@ -48,6 +49,7 @@ private:
     void restoreWindowState();
     void setColorsFromHistory(PaletteHistoryItem*, int);
     void closeEvent(QCloseEvent*);
+    void pickColor(int i);
 
 signals:
     void closed();