UI: Add up/down/left/right position shortcuts

Allows nudging of selected items in the direction pressed when the
preview window is focused.

obs/window-basic-main.cpp

@@ -164,6 +164,20 @@ OBSBasic::OBSBasic(QWidget *parent)
 	ui->action_Settings->setMenuRole(QAction::PreferencesRole);
 	ui->actionE_xit->setMenuRole(QAction::QuitRole);
 #endif
+
+	auto addNudge = [this](const QKeySequence &seq, const char *s)
+	{
+		QAction *nudge = new QAction(ui->preview);
+		nudge->setShortcut(seq);
+		nudge->setShortcutContext(Qt::WidgetShortcut);
+		ui->preview->addAction(nudge);
+		connect(nudge, SIGNAL(triggered()), this, s);
+	};
+
+	addNudge(Qt::Key_Up, SLOT(NudgeUp()));
+	addNudge(Qt::Key_Down, SLOT(NudgeDown()));
+	addNudge(Qt::Key_Left, SLOT(NudgeLeft()));
+	addNudge(Qt::Key_Right, SLOT(NudgeRight()));
 }
 
 static void SaveAudioDevice(const char *name, int channel, obs_data_t *parent)
@@ -2800,3 +2814,40 @@ void OBSBasic::TogglePreview()
 	ui->preview->setVisible(enabled);
 	ui->previewDisabledLabel->setVisible(!enabled);
 }
+
+void OBSBasic::Nudge(int dist, MoveDir dir)
+{
+	struct MoveInfo {
+		float dist;
+		MoveDir dir;
+	} info = {(float)dist, dir};
+
+	auto func = [] (obs_scene_t*, obs_sceneitem_t *item, void *param)
+	{
+		MoveInfo *info = reinterpret_cast<MoveInfo*>(param);
+		struct vec2 dir = {0.0f, 0.0f};
+		struct vec2 pos;
+
+		if (!obs_sceneitem_selected(item))
+			return true;
+
+		switch (info->dir) {
+		case MoveDir::Up:    dir.y = -info->dist; break;
+		case MoveDir::Down:  dir.y =  info->dist; break;
+		case MoveDir::Left:  dir.x = -info->dist; break;
+		case MoveDir::Right: dir.x =  info->dist; break;
+		}
+
+		obs_sceneitem_get_pos(item, &pos);
+		vec2_add(&pos, &pos, &dir);
+		obs_sceneitem_set_pos(item, &pos);
+		return true;
+	};
+
+	obs_scene_enum_items(GetCurrentScene(), func, &info);
+}
+
+void OBSBasic::NudgeUp()       {Nudge(1,  MoveDir::Up);}
+void OBSBasic::NudgeDown()     {Nudge(1,  MoveDir::Down);}
+void OBSBasic::NudgeLeft()     {Nudge(1,  MoveDir::Left);}
+void OBSBasic::NudgeRight()    {Nudge(1,  MoveDir::Right);}

obs/window-basic-main.hpp

@@ -55,6 +55,13 @@ class OBSBasic : public OBSMainWindow {
 
 	friend class OBSBasicPreview;
 
+	enum class MoveDir {
+		Up,
+		Down,
+		Left,
+		Right
+	};
+
 private:
 	std::unordered_map<obs_source_t*, int> sourceSceneRefs;
 
@@ -137,6 +144,8 @@ private:
 	void CreatePropertiesWindow(obs_source_t *source);
 	void CreateFiltersWindow(obs_source_t *source);
 
+	void Nudge(int dist, MoveDir dir);
+
 public slots:
 	void StreamingStart();
 	void StreamingStop(int errorcode);
@@ -311,6 +320,11 @@ private slots:
 
 	void TogglePreview();
 
+	void NudgeUp();
+	void NudgeDown();
+	void NudgeLeft();
+	void NudgeRight();
+
 public:
 	explicit OBSBasic(QWidget *parent = 0);
 	virtual ~OBSBasic();