--- /dev/null
+/*
+ * Copyright 2020 Olaf Wintermann
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "xdnd.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static Atom XdndAware;
+static Atom XdndSelection;
+static Atom XdndStatus;
+static Atom XdndActionCopy;
+static Atom XdndFinished;
+
+static Window src;
+
+static Atom selType;
+
+static int canDrop;
+
+XtCallbackProc dropCallback;
+XtPointer dropData;
+
+static void checkSelectionValue(Widget w, XtPointer clientData, Atom *selType,
+ Atom *type, XtPointer value, unsigned long *length, int *format)
+{
+ if(value) {
+ canDrop = 1; // we have a text/uri-list value
+ XtFree(value);
+ }
+}
+
+static void getSelectionValue(Widget w, XtPointer clientData, Atom *selType,
+ Atom *type, XtPointer value, unsigned long *length, int *format)
+{
+ if(value) {
+ if(dropCallback) {
+ dropCallback(w, value, dropData);
+ }
+ XtFree(value);
+
+ // XdndFinished
+ if(src != 0) {
+ XEvent msg;
+ memset(&msg, 0, sizeof(XEvent));
+ msg.xany.type = ClientMessage;
+ msg.xany.display = XtDisplay(w);
+ msg.xclient.window = src;
+ msg.xclient.message_type = XdndFinished;
+ msg.xclient.format = 32;
+ msg.xclient.data.l[0] = XtWindow(w);
+ XSendEvent(XtDisplay(w), msg.xclient.window, 0, 0, &msg);
+ src = 0;
+ }
+ }
+}
+
+static void xdnd_enter(Widget w, XEvent *event, String *args, Cardinal *nArgs) {
+ //printf("xdnd_enter\n");
+ XtGetSelectionValue(w, XdndSelection, selType, checkSelectionValue, NULL, 0);
+}
+
+static void xdnd_position(Widget w, XEvent *event, String *args, Cardinal *nArgs) {
+ //printf("xdnd_position\n");
+
+ src = event->xclient.data.l[0];
+
+ XEvent msg;
+ memset(&msg, 0, sizeof(XEvent));
+ msg.xany.type = ClientMessage;
+ msg.xany.display = XtDisplay(w);
+ msg.xclient.window = src;
+ msg.xclient.message_type = XdndStatus;
+ msg.xclient.format = 32;
+ msg.xclient.data.l[0] = XtWindow(w);
+ msg.xclient.data.l[1] = canDrop;
+ msg.xclient.data.l[4] = XdndActionCopy;
+ XSendEvent(XtDisplay(w), msg.xclient.window, 0, 0, &msg);
+}
+
+static void xdnd_drop(Widget w, XEvent *event, String *args, Cardinal *nArgs) {
+ //printf("xdnd_drop\n");
+
+ XtGetSelectionValue(w, XdndSelection, selType, getSelectionValue, NULL, 0);
+
+ canDrop = 0;
+}
+
+static void xdnd_leave(Widget w, XEvent *event, String *args, Cardinal *nArgs) {
+ //printf("xdnd_leave\n");
+ canDrop = 0;
+}
+
+static XtActionsRec xdndactions[] = {
+ {"xdnd_enter", xdnd_enter},
+ {"xdnd_position", xdnd_position},
+ {"xdnd_drop", xdnd_drop},
+ {"xdnd_leave", xdnd_leave}
+};
+
+
+void XdndInit(
+ Display *dpy,
+ XtAppContext app,
+ XtCallbackProc dropCB,
+ XtPointer dropCBData)
+{
+ // init atoms
+ XdndAware = XInternAtom(dpy, "XdndAware", False);
+ XdndSelection = XInternAtom(dpy, "XdndSelection", False);
+ XdndStatus = XInternAtom(dpy, "XdndStatus", False);
+ XdndActionCopy = XInternAtom(dpy, "XdndActionCopy", False);
+ XdndFinished = XInternAtom(dpy, "XdndFinished", False);
+ selType = XInternAtom(dpy, "text/uri-list", False);
+
+ XtAppAddActions(
+ app,
+ xdndactions,
+ sizeof(xdndactions) / sizeof(XtActionsRec));
+
+ dropCallback = dropCB;
+ dropData = dropCBData;
+}
+
+void XdndEnable(Widget w) {
+ int version = 4;
+ XChangeProperty(
+ XtDisplay(w),
+ XtWindow(w),
+ XdndAware,
+ XA_ATOM,
+ 32,
+ PropModeReplace,
+ (XtPointer)&version,
+ 1);
+
+ if(XtIsShell(w)) {
+ XtOverrideTranslations(w, XtParseTranslationTable(
+ "<Message>XdndEnter: xdnd_enter()\n"
+ "<Message>XdndPosition: xdnd_position()\n"
+ "<Message>XdndDrop: xdnd_drop()\n"
+ "<Message>XdndLeave: xdnd_leave()\n"));
+ }
+}
--- /dev/null
+/*
+ * Copyright 2020 Olaf Wintermann
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef XNEDIT_XDND_H
+#define XNEDIT_XDND_H
+
+#include <Xm/Xm.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void XdndInit(
+ Display *dpy,
+ XtAppContext app,
+ XtCallbackProc dropCB,
+ XtPointer dropCBData);
+
+void XdndEnable(Widget w);
+
+
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* XNEDIT_XDND_H */
+