add xdnd code from xnedit

diff --git a/application/Makefile b/application/Makefile
index 97ddd55..db09a6c 100644 (file)
--- a/application/Makefile
+++ b/application/Makefile
@@ -39,6 +39,7 @@ SRC += settings.c
 SRC += utils.c
 SRC += json.c
 SRC += Sidebar.c
+SRC += xdnd.c
 
 OBJ = $(SRC:%.c=$(BUILD_ROOT)/build/application/%.$(OBJ_EXT))
 

diff --git a/application/xdnd.c b/application/xdnd.c
new file mode 100644 (file)
index 0000000..09b10eb
--- /dev/null
+++ b/application/xdnd.c
@@ -0,0 +1,164 @@
+/*
+ * 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"));
+    }
+}

diff --git a/application/xdnd.h b/application/xdnd.h
new file mode 100644 (file)
index 0000000..a391066
--- /dev/null
+++ b/application/xdnd.h
@@ -0,0 +1,48 @@
+/*
+ * 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 */
+