[PATCH libinput 14/15] tablet: add support for libinput_tool_has_button

[Peter Hutterer]

The mouse like devices have LMR, SIDE and EXTRA.
PENCIL (which is the Wacom Inking) and the eraser have no buttons.
AIRBRUSH has only one button, all other pens have two.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev-tablet.c     | 41 +++++++++++++++++++++++++++++++++++++++++
 src/libinput-private.h |  1 +
 src/libinput.c         | 11 +++++++++++
 src/libinput.h         | 15 +++++++++++++++
 src/libinput.sym       |  1 +
 5 files changed, 69 insertions(+)

diff --git a/src/evdev-tablet.c b/src/evdev-tablet.c
index dcf1716..6ae9c6e 100644
--- a/src/evdev-tablet.c
+++ b/src/evdev-tablet.c
@@ -401,6 +401,16 @@ copy_axis_cap(const struct tablet_dispatch *tablet,
 		set_bit(tool->axis_caps, axis);
 }
 
+static inline void
+copy_button_cap(const struct tablet_dispatch *tablet,
+		struct libinput_tool *tool,
+		uint32_t button)
+{
+	struct libevdev *evdev = tablet->device->evdev;
+	if (libevdev_has_event_code(evdev, EV_KEY, button))
+		set_bit(tool->buttons, button);
+}
+
 static void
 tool_set_bits(const struct tablet_dispatch *tablet,
 	      struct libinput_tool *tool,
@@ -447,6 +457,37 @@ tool_set_bits(const struct tablet_dispatch *tablet,
 	default:
 		break;
 	}
+
+	/* Button capabilities on the various tools:
+	 * - all pens have BTN_TOUCH
+	 * - the eraser and the pencil (Wacom Inking) have no buttons
+	 * - the airbrush only has a single button
+	 * - all other pens have 2 buttons
+	 * - the mouse has the first 5 mouse buttons
+	 */
+	switch (type) {
+	case LIBINPUT_TOOL_PEN:
+	case LIBINPUT_TOOL_BRUSH:
+		copy_button_cap(tablet, tool, BTN_STYLUS2);
+		/* fallthrough */
+	case LIBINPUT_TOOL_AIRBRUSH:
+		copy_button_cap(tablet, tool, BTN_STYLUS);
+		/* fallthrough */
+	case LIBINPUT_TOOL_PENCIL:
+	case LIBINPUT_TOOL_ERASER:
+		copy_button_cap(tablet, tool, BTN_TOUCH);
+		break;
+	case LIBINPUT_TOOL_MOUSE:
+	case LIBINPUT_TOOL_LENS:
+		copy_button_cap(tablet, tool, BTN_LEFT);
+		copy_button_cap(tablet, tool, BTN_MIDDLE);
+		copy_button_cap(tablet, tool, BTN_RIGHT);
+		copy_button_cap(tablet, tool, BTN_SIDE);
+		copy_button_cap(tablet, tool, BTN_EXTRA);
+		break;
+	default:
+		break;
+	}
 }
 
 static struct libinput_tool *
diff --git a/src/libinput-private.h b/src/libinput-private.h
index 0b01029..4fd8fa6 100644
--- a/src/libinput-private.h
+++ b/src/libinput-private.h
@@ -190,6 +190,7 @@ struct libinput_tool {
 	uint32_t serial;
 	enum libinput_tool_type type;
 	unsigned char axis_caps[NCHARS(LIBINPUT_TABLET_AXIS_MAX + 1)];
+	unsigned char buttons[NCHARS(KEY_MAX) + 1];
 	int refcount;
 	void *user_data;
 };
diff --git a/src/libinput.c b/src/libinput.c
index 7c90f37..3a8c07f 100644
--- a/src/libinput.c
+++ b/src/libinput.c
@@ -677,6 +677,17 @@ libinput_tool_has_axis(struct libinput_tool *tool,
 	return bit_is_set(tool->axis_caps, axis);
 }
 
+LIBINPUT_EXPORT int
+libinput_tool_has_button(struct libinput_tool *tool,
+			 uint32_t code)
+{
+	if (NCHARS(code) > sizeof(tool->buttons))
+		return 0;
+
+	return bit_is_set(tool->buttons, code);
+}
+
+
 LIBINPUT_EXPORT void
 libinput_tool_set_user_data(struct libinput_tool *tool,
 			    void *user_data)
diff --git a/src/libinput.h b/src/libinput.h
index 461925a..36c0931 100644
--- a/src/libinput.h
+++ b/src/libinput.h
@@ -1222,6 +1222,21 @@ libinput_tool_has_axis(struct libinput_tool *tool,
 /**
  * @ingroup event_tablet
  *
+ * Check if a tablet tool has a button with the
+ * passed-in code (see linux/input.h).
+ *
+ * @param tool A tablet tool
+ * @param code button code to check for
+ *
+ * @return 1 if the tool supports this button code, 0 if it does not
+ */
+int
+libinput_tool_has_button(struct libinput_tool *tool,
+		         uint32_t code);
+
+/**
+ * @ingroup event_tablet
+ *
  * Decrement the ref count of tool by one. When the ref count of tool reaches 0,
  * the memory allocated for tool will be freed.
  *
diff --git a/src/libinput.sym b/src/libinput.sym
index b31c231..c4b5344 100644
--- a/src/libinput.sym
+++ b/src/libinput.sym
@@ -155,6 +155,7 @@ LIBINPUT_TABLET_SUPPORT {
 	libinput_tool_get_serial;
 	libinput_tool_get_type;
 	libinput_tool_get_user_data;
+	libinput_tool_has_button;
 	libinput_tool_has_axis;
 	libinput_tool_ref;
 	libinput_tool_set_user_data;
-- 
2.1.0