From b5855e5deb7482f96e1a0217218442ecdf21e3ab Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Thu, 30 Dec 2021 15:46:00 +0100
Subject: [PATCH] Add relative mode flag to mouse processors

The default mouse injection works in absolute mode: it forwards clicks
at a specific position on screen.

To support HID mouse, add a flag to indicate that the mouse processor
works in relative mode: it forwards mouse motion vectors, without any
absolute reference to the screen.
---
 app/src/input_manager.c         | 10 ++++++++++
 app/src/mouse_inject.c          |  2 ++
 app/src/trait/mouse_processor.h |  7 +++++++
 3 files changed, 19 insertions(+)

diff --git a/app/src/input_manager.c b/app/src/input_manager.c
index 64922f28..5cfb5b7e 100644
--- a/app/src/input_manager.c
+++ b/app/src/input_manager.c
@@ -659,7 +659,11 @@ input_manager_process_mouse_motion(struct input_manager *im,
     assert(im->mp->ops->process_mouse_motion);
     im->mp->ops->process_mouse_motion(im->mp, &evt);
 
+    // vfinger must never be used in relative mode
+    assert(!im->mp->relative_mode || !im->vfinger_down);
+
     if (im->vfinger_down) {
+        assert(!im->mp->relative_mode); // assert one more time
         struct sc_point mouse =
             screen_convert_window_to_frame_coords(im->screen, event->x,
                                                   event->y);
@@ -772,6 +776,12 @@ input_manager_process_mouse_button(struct input_manager *im,
     assert(im->mp->ops->process_mouse_click);
     im->mp->ops->process_mouse_click(im->mp, &evt);
 
+    if (im->mp->relative_mode) {
+        assert(!im->vfinger_down); // vfinger must not be used in relative mode
+        // No pinch-to-zoom simulation
+        return;
+    }
+
     // Pinch-to-zoom simulation.
     //
     // If Ctrl is hold when the left-click button is pressed, then
diff --git a/app/src/mouse_inject.c b/app/src/mouse_inject.c
index 38bfa404..dcb4f611 100644
--- a/app/src/mouse_inject.c
+++ b/app/src/mouse_inject.c
@@ -151,4 +151,6 @@ sc_mouse_inject_init(struct sc_mouse_inject *mi,
     };
 
     mi->mouse_processor.ops = &ops;
+
+    mi->mouse_processor.relative_mode = false;
 }
diff --git a/app/src/trait/mouse_processor.h b/app/src/trait/mouse_processor.h
index 0252d2c6..6e0b596e 100644
--- a/app/src/trait/mouse_processor.h
+++ b/app/src/trait/mouse_processor.h
@@ -16,6 +16,13 @@
  */
 struct sc_mouse_processor {
     const struct sc_mouse_processor_ops *ops;
+
+    /**
+     * If set, the mouse processor works in relative mode (the absolute
+     * position is irrelevant). In particular, it indicates that the mouse
+     * pointer must be "captured" by the UI.
+     */
+    bool relative_mode;
 };
 
 struct sc_mouse_processor_ops {