From f20c07d757388482ff2f4ca4eb7ceaf52712814a Mon Sep 17 00:00:00 2001
From: ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
Date: Thu, 18 Jul 2019 17:46:10 +0200
Subject: X11: support copy/paste of image via clipboard within a single app

X11 requires to process differently paste if both copy and paste are within the
same app or are in 2 separate apps. This was implemented for paste of text.
It's now also implemented for paste of image.
---
 src/Fl_x.cxx | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 50 insertions(+), 8 deletions(-)

(limited to 'src')

diff --git a/src/Fl_x.cxx b/src/Fl_x.cxx
index 36418ffe8..6c1da73a4 100644
--- a/src/Fl_x.cxx
+++ b/src/Fl_x.cxx
@@ -751,18 +751,56 @@ const char * fl_selection_type[2];
 int fl_selection_buffer_length[2];
 char fl_i_own_selection[2] = {0,0};
 
+static void read_int(uchar *c, int& i) {
+  i = *c;
+  i |= (*(++c))<<8;
+  i |= (*(++c))<<16;
+  i |= (*(++c))<<24;
+}
+
+// turn BMP image FLTK produced by create_bmp() back to Fl_RGB_Image
+static Fl_RGB_Image *own_bmp_to_RGB(char *bmp) {
+  int w, h;
+  read_int((uchar*)bmp + 18, w);
+  read_int((uchar*)bmp + 22, h);
+  int R=(3*w+3)/4 * 4; // the number of bytes per row, rounded up to multiple of 4
+  bmp +=  54;
+  uchar *data = new uchar[w*h*3];
+  uchar *p = data;
+  for (int i = h-1; i >= 0; i--) {
+    char *s = bmp + i * R;
+    for (int j = 0; j < w; j++) {
+      *p++=s[2];
+      *p++=s[1];
+      *p++=s[0];
+      s+=3;
+    }
+  }
+  Fl_RGB_Image *img = new Fl_RGB_Image(data, w, h, 3);
+  img->alloc_array = 1;
+  return img;
+}
+
 // Call this when a "paste" operation happens:
 void Fl_X11_System_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
   if (fl_i_own_selection[clipboard]) {
     // We already have it, do it quickly without window server.
-    // Notice that the text is clobbered if set_selection is
-    // called in response to FL_PASTE!
-    // However, for now, we only paste text in this function
-    if (fl_selection_type[clipboard] != Fl::clipboard_plain_text) return; //TODO: allow copy/paste of image within same app
-    Fl::e_text = fl_selection_buffer[clipboard];
-    Fl::e_length = fl_selection_length[clipboard];
-    if (!Fl::e_text) Fl::e_text = (char *)"";
-    receiver.handle(FL_PASTE);
+    if (type == Fl::clipboard_plain_text && fl_selection_type[clipboard] == type) {
+      // Notice that the text is clobbered if set_selection is
+      // called in response to FL_PASTE!
+      // However, for now, we only paste text in this function
+      Fl::e_text = fl_selection_buffer[clipboard];
+      Fl::e_length = fl_selection_length[clipboard];
+      if (!Fl::e_text) Fl::e_text = (char *)"";
+    } else if (clipboard == 1 && type == Fl::clipboard_image && fl_selection_type[1] == type) {
+      Fl::e_clipboard_data = own_bmp_to_RGB(fl_selection_buffer[1]);
+      Fl::e_clipboard_type = Fl::clipboard_image;
+    } else return;
+    int retval = receiver.handle(FL_PASTE);
+    if (retval == 0 && type == Fl::clipboard_image) {
+      delete (Fl_RGB_Image*)Fl::e_clipboard_data;
+      Fl::e_clipboard_data = NULL;
+    }
     return;
   }
   // otherwise get the window server to return it:
@@ -775,11 +813,15 @@ void Fl_X11_System_Driver::paste(Fl_Widget &receiver, int clipboard, const char
 
 int Fl_X11_System_Driver::clipboard_contains(const char *type)
 {
+  if (fl_i_own_selection[1]) {
+    return fl_selection_type[1] == type;
+  }
   XEvent event;
   Atom actual; int format; unsigned long count, remaining, i = 0;
   unsigned char* portion = NULL;
   Fl_Window *win = Fl::first_window();
   if (!win || !fl_xid(win)) return 0;
+  win->wait_for_expose();
   XConvertSelection(fl_display, CLIPBOARD, TARGETS, CLIPBOARD, fl_xid(win), CurrentTime);
   XFlush(fl_display);
   do  { 
-- 
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