implement gestures

1 files changed, 72 insertions, 4 deletions

diff --git a/dwl.c b/dwl.c
index 0f069ad..3c690cd 100644
--- a/dwl.c
+++ b/dwl.c
@@ -89,6 +89,7 @@
 enum { CurNormal, CurPressed, CurMove, CurResize }; /* cursor */
 enum { XDGShell, LayerShell, X11 }; /* client types */
 enum { LyrBg, LyrBottom, LyrTile, LyrFloat, LyrTop, LyrFS, LyrOverlay, LyrBlock, NUM_LAYERS }; /* scene layers */
+enum { SWIPE_LEFT, SWIPE_RIGHT, SWIPE_DOWN, SWIPE_UP };
 
 typedef struct ForceTearingRule {
 	const char* title;
@@ -109,6 +110,14 @@ typedef struct {
 	const Arg arg;
 } Button;
 
+typedef struct {
+  unsigned int mod;
+  unsigned int motion;
+  unsigned int fingers_count;
+  void (*func)(const Arg *);
+  const Arg arg;
+} Gesture;
+
 typedef struct Monitor Monitor;
 typedef struct {
 	/* Must keep this field first */
@@ -281,6 +290,7 @@ static void arrangelayer(Monitor *m, struct wl_list *list,
 static void arrangelayers(Monitor *m);
 static void axisnotify(struct wl_listener *listener, void *data);
 static void buttonpress(struct wl_listener *listener, void *data);
+static int ongesture(struct wlr_pointer_swipe_end_event *event);
 static void swipe_begin(struct wl_listener *listener, void *data);
 static void swipe_update(struct wl_listener *listener, void *data);
 static void swipe_end(struct wl_listener *listener, void *data);
@@ -476,6 +486,10 @@ static struct wlr_box sgeom;
 static struct wl_list mons;
 static Monitor *selmon;
 
+static uint32_t swipe_fingers = 0;
+static double swipe_dx = 0;
+static double swipe_dy = 0;
+
 static int enablegaps = 1;   /* enables gaps, used by togglegaps */
 
 /* global event handlers */
@@ -531,6 +545,8 @@ static struct wlr_xwayland *xwayland;
 /* attempt to encapsulate suck into one file */
 #include "client.h"
 
+static const unsigned int abzsquare = swipe_min_threshold * swipe_min_threshold;
+
 /* function implementations */
 void
 applybounds(Client *c, struct wlr_box *bbox)
@@ -754,9 +770,14 @@ swipe_begin(struct wl_listener *listener, void *data)
 {
 	struct wlr_pointer_swipe_begin_event *event = data;
 
+  swipe_fingers = event->fingers;
+  // Reset swipe distance at the beginning of a swipe
+  swipe_dx = 0;
+  swipe_dy = 0;
+
 	// Forward swipe begin event to client
 	wlr_pointer_gestures_v1_send_swipe_begin(
-		pointer_gestures, 
+		pointer_gestures,
 		seat,
 		event->time_msec,
 		event->fingers
@@ -768,9 +789,14 @@ swipe_update(struct wl_listener *listener, void *data)
 {
 	struct wlr_pointer_swipe_update_event *event = data;
 
+	swipe_fingers = event->fingers;
+	// Accumulate swipe distance
+	swipe_dx += event->dx;
+	swipe_dy += event->dy;
+
 	// Forward swipe update event to client
 	wlr_pointer_gestures_v1_send_swipe_update(
-		pointer_gestures, 
+		pointer_gestures,
 		seat,
 		event->time_msec,
 		event->dx,
@@ -778,14 +804,56 @@ swipe_update(struct wl_listener *listener, void *data)
 	);
 }
 
+int
+ongesture(struct wlr_pointer_swipe_end_event *event)
+{
+  struct wlr_keyboard *keyboard;
+  uint32_t mods;
+  const Gesture *g;
+  unsigned int motion;
+  unsigned int adx = (int)round(fabs(swipe_dx));
+  unsigned int ady = (int)round(fabs(swipe_dy));
+  int handled = 0;
+
+  if (event->cancelled) {
+    return handled;
+  }
+
+  // Require absolute distance movement beyond a small thresh-hold
+  if (adx * adx + ady * ady < abzsquare) {
+    return handled;
+  }
+
+  if (adx > ady) {
+    motion = swipe_dx < 0 ? SWIPE_LEFT : SWIPE_RIGHT;
+  } else {
+    motion = swipe_dy < 0 ? SWIPE_UP : SWIPE_DOWN;
+  }
+
+  keyboard = wlr_seat_get_keyboard(seat);
+  mods = keyboard ? wlr_keyboard_get_modifiers(keyboard) : 0;
+  for (g = gestures; g < END(gestures); g++) {
+    if (CLEANMASK(mods) == CLEANMASK(g->mod) &&
+      swipe_fingers == g->fingers_count &&
+      motion == g->motion && g->func) {
+      g->func(&g->arg);
+      handled = 1;
+    }
+  }
+  return handled;
+}
+
 void
 swipe_end(struct wl_listener *listener, void *data)
 {
 	struct wlr_pointer_swipe_end_event *event = data;
 
+  // TODO: should we stop here if the event has been handled?
+  ongesture(event);
+
 	// Forward swipe end event to client
 	wlr_pointer_gestures_v1_send_swipe_end(
-		pointer_gestures, 
+		pointer_gestures,
 		seat,
 		event->time_msec,
 		event->cancelled
@@ -799,7 +867,7 @@ pinch_begin(struct wl_listener *listener, void *data)
 
 	// Forward pinch begin event to client
 	wlr_pointer_gestures_v1_send_pinch_begin(
-		pointer_gestures, 
+		pointer_gestures,
 		seat,
 		event->time_msec,
 		event->fingers