1 files changed, 162 insertions, 0 deletions
diff --git a/src/ui/tool/event-utils.cpp b/src/ui/tool/event-utils.cpp
new file mode 100644
index 0000000..33a196d
--- /dev/null
+++ b/src/ui/tool/event-utils.cpp
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * Collection of shorthands to deal with GDK events.
+ */
+/* Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2009 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstring>
+#include <gdk/gdk.h>
+#include <gdk/gdkkeysyms.h>
+#include <gdkmm/display.h>
+#include "display/sp-canvas.h"
+#include "ui/tool/event-utils.h"
+
+namespace Inkscape {
+namespace UI {
+
+
+guint shortcut_key(GdkEventKey const &event)
+{
+    guint shortcut_key = 0;
+    gdk_keymap_translate_keyboard_state(
+            Gdk::Display::get_default()->get_keymap(),
+            event.hardware_keycode,
+            (GdkModifierType) event.state,
+            0   /*event->key.group*/,
+            &shortcut_key, nullptr, nullptr, nullptr);
+    return shortcut_key;
+}
+
+unsigned combine_key_events(guint keyval, gint mask)
+{
+    GdkEvent *event_next;
+    gint i = 0;
+
+    event_next = gdk_event_get();
+    // while the next event is also a key notify with the same keyval and mask,
+    while (event_next && (event_next->type == GDK_KEY_PRESS || event_next->type == GDK_KEY_RELEASE)
+           && event_next->key.keyval == keyval
+           && (!mask || event_next->key.state & mask)) {
+        if (event_next->type == GDK_KEY_PRESS)
+            i ++;
+        // kill it
+        gdk_event_free(event_next);
+        // get next
+        event_next = gdk_event_get();
+    }
+    // otherwise, put it back onto the queue
+    if (event_next) gdk_event_put(event_next);
+
+    return i;
+}
+
+unsigned combine_motion_events(SPCanvas *canvas, GdkEventMotion &event, gint mask)
+{
+    if (canvas == nullptr) {
+        return false;
+    }
+    GdkEvent *event_next;
+    gint i = 0;
+    event.x -= canvas->_x0;
+    event.y -= canvas->_y0;
+
+    event_next = gdk_event_get();
+    // while the next event is also a motion notify
+    while (event_next && (event_next->type == GDK_MOTION_NOTIFY)
+            && (!mask || event_next->motion.state & mask))
+    {
+        if (event_next->motion.device == event.device) {
+            GdkEventMotion &next = event_next->motion;
+            event.send_event = next.send_event;
+            event.time = next.time;
+            event.x = next.x;
+            event.y = next.y;
+            event.state = next.state;
+            event.is_hint = next.is_hint;
+            event.x_root = next.x_root;
+            event.y_root = next.y_root;
+            if (event.axes && next.axes) {
+                memcpy(event.axes, next.axes, gdk_device_get_n_axes(event.device));
+            }
+        }
+
+        // kill it
+        gdk_event_free(event_next);
+        event_next = gdk_event_get();
+        i++;
+    }
+    // otherwise, put it back onto the queue
+    if (event_next) {
+        gdk_event_put(event_next);
+    }
+    event.x += canvas->_x0;
+    event.y += canvas->_y0;
+
+    return i;
+}
+
+/** Returns the modifier state valid after this event. Use this when you process events
+ * that change the modifier state. Currently handles only Shift, Ctrl, Alt. */
+unsigned state_after_event(GdkEvent *event)
+{
+    unsigned state = 0;
+    switch (event->type) {
+    case GDK_KEY_PRESS:
+        state = event->key.state;
+        switch(shortcut_key(event->key)) {
+        case GDK_KEY_Shift_L:
+        case GDK_KEY_Shift_R:
+            state |= GDK_SHIFT_MASK;
+            break;
+        case GDK_KEY_Control_L:
+        case GDK_KEY_Control_R:
+            state |= GDK_CONTROL_MASK;
+            break;
+        case GDK_KEY_Alt_L:
+        case GDK_KEY_Alt_R:
+            state |= GDK_MOD1_MASK;
+            break;
+        default: break;
+        }
+        break;
+    case GDK_KEY_RELEASE:
+        state = event->key.state;
+        switch(shortcut_key(event->key)) {
+        case GDK_KEY_Shift_L:
+        case GDK_KEY_Shift_R:
+            state &= ~GDK_SHIFT_MASK;
+            break;
+        case GDK_KEY_Control_L:
+        case GDK_KEY_Control_R:
+            state &= ~GDK_CONTROL_MASK;
+            break;
+        case GDK_KEY_Alt_L:
+        case GDK_KEY_Alt_R:
+            state &= ~GDK_MOD1_MASK;
+            break;
+        default: break;
+        }
+        break;
+    default: break;
+    }
+    return state;
+}
+
+} // namespace UI
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :