ptz-controls: Add hotkeys for selection relative preset recall

data/locale/en-GB.ini

@@ -34,6 +34,9 @@ PTZ.Action.Preset.Save="Save Camera Preset"
 PTZ.Action.Preset.Clear="Clear Camera Preset"
 PTZ.Action.Preset.RecallNum="Camera Recall #%1"
 PTZ.Action.Preset.SaveNum="Camera Save #%1"
+PTZ.Action.Preset.Prev="Previous Preset"
+PTZ.Action.Preset.Next="Next Preset"
+PTZ.Action.Preset.RecallSelected="Recall Selected Preset"
 PTZ.Action.Preset.Add.Tooltip="Add Preset"
 PTZ.Action.Preset.MoveUp.Tooltip="Move Preset Up"
 PTZ.Action.Preset.MoveDown.Tooltip="Move Preset Down"

src/ptz-controls.cpp

@@ -317,6 +317,28 @@ PTZControls::PTZControls(QWidget *parent) : QFrame(parent), ui(new Ui::PTZContro
 		hotkey = registerHotkey(QT_TO_UTF8(name), QT_TO_UTF8(description), preset_set_cb, this);
 		preset_hotkey_map[hotkey] = i;
 	}
+
+	registerHotkey(
+		"PTZ.PresetPrev", obs_module_text("PTZ.Action.Preset.Prev"),
+		[](void *ptz_data, obs_hotkey_id, obs_hotkey_t *, bool pressed) {
+			if (pressed)
+				static_cast<PTZControls *>(ptz_data)->presetStep(-1);
+		},
+		this);
+	registerHotkey(
+		"PTZ.PresetNext", obs_module_text("PTZ.Action.Preset.Next"),
+		[](void *ptz_data, obs_hotkey_id, obs_hotkey_t *, bool pressed) {
+			if (pressed)
+				static_cast<PTZControls *>(ptz_data)->presetStep(1);
+		},
+		this);
+	registerHotkey(
+		"PTZ.PresetRecallSelected", obs_module_text("PTZ.Action.Preset.RecallSelected"),
+		[](void *ptz_data, obs_hotkey_id, obs_hotkey_t *, bool pressed) {
+			if (pressed)
+				static_cast<PTZControls *>(ptz_data)->presetRecallSelected();
+		},
+		this);
 }
 
 #if defined(ENABLE_JOYSTICK)
@@ -979,6 +1001,38 @@ void PTZControls::presetReset(long long preset_id)
 	callCurrentDevice("ptz_preset_clear", "preset_id", preset_id);
 }
 
+/* Move the preset selection without recalling anything, so that a controller
+ * can browse the preset list and then trigger it with a separate button. Wraps
+ * around at both ends; with nothing selected yet, step forwards from the top
+ * and backwards from the bottom. */
+void PTZControls::presetStep(int step)
+{
+	auto model = ui->presetListView->model();
+	if (!model)
+		return;
+	const int count = model->rowCount();
+	if (count < 1)
+		return;
+	const int current = ui->presetListView->currentIndex().row();
+	int next;
+	if (current < 0)
+		next = step > 0 ? 0 : count - 1;
+	else
+		next = ((current + step) % count + count) % count;
+	ui->presetListView->setCurrentIndex(model->index(next, 0));
+}
+
+/* Recall whatever preset is currently highlighted in the list. The numbered
+ * PTZ.Recall<n> hotkeys address a fixed preset; this one follows the
+ * selection, which is what makes browse-then-activate possible from a
+ * joystick or a keyboard. */
+void PTZControls::presetRecallSelected()
+{
+	auto id = presetIndexToId(ui->presetListView->currentIndex());
+	if (id >= 0)
+		presetRecall(id);
+}
+
 int PTZControls::presetIndexToId(QModelIndex index)
 {
 	if (index.isValid())

src/ptz-controls.hpp

@@ -75,6 +75,8 @@ class PTZControls : public QFrame {
 	void presetSet(long long id);
 	void presetRecall(long long id);
 	void presetReset(long long id);
+	void presetStep(int step);
+	void presetRecallSelected();
 	void setAutofocusEnabled(bool autofocus_on);
 
 	bool callCurrentDevice(const char *method, calldata_t *cd = nullptr) const;