[PATCH libinput 04/10] Add a config interface for scroll methods

[Peter Hutterer]

---
 src/libinput-private.h |  9 ++++++
 src/libinput.c         | 35 ++++++++++++++++++++++++
 src/libinput.h         | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 118 insertions(+)

diff --git a/src/libinput-private.h b/src/libinput-private.h
index 020167e..d3570a4 100644
--- a/src/libinput-private.h
+++ b/src/libinput-private.h
@@ -77,8 +77,17 @@ struct libinput_device_config_tap {
 	void (*reset)(struct libinput_device *device);
 };
 
+struct libinput_device_config_scroll {
+	int (*methods)(struct libinput_device *device);
+	enum libinput_config_status (*set)(struct libinput_device *device,
+					   enum libinput_scroll_method method);
+	enum libinput_scroll_method (*get)(struct libinput_device *device);
+	void (*reset)(struct libinput_device *device);
+};
+
 struct libinput_device_config {
 	struct libinput_device_config_tap *tap;
+	struct libinput_device_config_scroll *scroll;
 };
 
 struct libinput_device {
diff --git a/src/libinput.c b/src/libinput.c
index 6a713bb..b2388e6 100644
--- a/src/libinput.c
+++ b/src/libinput.c
@@ -1215,3 +1215,38 @@ libinput_device_config_tap_reset(struct libinput_device *device)
 	if (device->config.tap)
 		device->config.tap->reset(device);
 }
+
+LIBINPUT_EXPORT unsigned int
+libinput_device_config_scroll_get_methods(struct libinput_device *device)
+{
+	return device->config.scroll ?
+			device->config.scroll->methods(device) :
+			LIBINPUT_SCROLL_METHOD_NONE;
+}
+
+LIBINPUT_EXPORT enum libinput_config_status
+libinput_device_config_scroll_set_method(struct libinput_device *device,
+					 enum libinput_scroll_method method)
+{
+	if ((method & libinput_device_config_scroll_get_methods(device)) == 0)
+		return LIBINPUT_CONFIG_STATUS_UNSUPPORTED;
+
+	return device->config.scroll->set(device, method);
+}
+
+LIBINPUT_EXPORT enum libinput_scroll_method
+libinput_device_config_scroll_get_method(struct libinput_device *device)
+{
+	if (libinput_device_config_scroll_get_methods(device) ==
+	    LIBINPUT_SCROLL_METHOD_NONE)
+		return LIBINPUT_SCROLL_METHOD_NONE;
+
+	return device->config.scroll->get(device);
+}
+
+LIBINPUT_EXPORT void
+libinput_device_config_scroll_reset(struct libinput_device *device)
+{
+	if (device->config.scroll)
+		device->config.scroll->reset(device);
+}
diff --git a/src/libinput.h b/src/libinput.h
index 0c84547..571f7ba 100644
--- a/src/libinput.h
+++ b/src/libinput.h
@@ -1434,6 +1434,80 @@ libinput_device_config_tap_is_enabled(struct libinput_device *device);
 void
 libinput_device_config_tap_reset(struct libinput_device *device);
 
+/**
+ * @ingroup config
+ *
+ * Devices without a physical scroll wheel (such as touchpads) may emulate
+ * scroll events in software through one or more methods.
+ */
+enum libinput_scroll_method {
+	/**
+	 * No scroll method available or selected.
+	 */
+	LIBINPUT_SCROLL_METHOD_NONE = 0,
+	/**
+	 * Scrolling is triggered by moving a finger at the edge of the
+	 * touchpad.
+	 */
+	LIBINPUT_SCROLL_METHOD_EDGE = (1 << 0),
+	/**
+	 * Scrolling is triggered by moving two fingers simultaneously.
+	 */
+	LIBINPUT_SCROLL_METHOD_TWOFINGER = (1 << 1),
+};
+
+/**
+ * @ingroup config
+ *
+ * Check the available scroll methods on this device.
+ *
+ * @param device The device to configure
+ *
+ * @return A bitmask of the available scroll methods
+ */
+unsigned int
+libinput_device_config_scroll_get_methods(struct libinput_device *device);
+
+/**
+ * @ingroup config
+ *
+ * Set the scroll method on this device. Only one method at a time may be
+ * chosen for each device.
+ *
+ * @param device The device to configure
+ * @param method The scroll method to chose
+ *
+ * @return A config status code
+ */
+enum libinput_config_status
+libinput_device_config_scroll_set_method(struct libinput_device *device,
+					 enum libinput_scroll_method method);
+
+/**
+ * @ingroup config
+ *
+ * Get the currently selected scroll method on this device. If a device does
+ * not support configurable scroll methods, the return value is always
+ * LIBINPUT_SCROLL_METHOD_NONE.
+ *
+ * @param device The device to configure
+ *
+ * @return The currently selected scroll method
+ */
+enum libinput_scroll_method
+libinput_device_config_scroll_get_method(struct libinput_device *device);
+
+/**
+ * @ingroup config
+ *
+ * Reset to the default scroll method for this device, if any. If the device
+ * does not support configurable scroll methods this function does nothing.
+ *
+ * @param device The device to configure
+ */
+void
+libinput_device_config_scroll_reset(struct libinput_device *device);
+
 #ifdef __cplusplus
 }
 #endif
-- 
1.9.0