shithub: puzzles

Download patch

ref: ad7042db989eb525defea9298b2b14d564498473
parent: c8cc4a5f387774c35e3e8f924d4200c0908c9d5a
author: Ben Harris <bjh21@bjh21.me.uk>
date: Wed Jul 5 15:39:57 EDT 2023 

js: Copy-to-clipboard support

Now using the browser's "copy" operation while the focus is in the
puzzle will copy the puzzle state to the clipboard.  Browsers seem to
have odd ideas about whate element to target with the "copy" event:
Firefox targets the parent of the <canvas> while Chromium targets the
<body>.  To cope with these and possible future weirdness I attach the
event handler to the document and then look to see if it's plausibly
related to the canvas.

Arguably we might want to handle a wider range of "copy" events, maybe
any where the selection isn't empty.  I'm not sure, though, so we'll
start with the minimal change.


--- a/cmake/platforms/emscripten.cmake
+++ b/cmake/platforms/emscripten.cmake
@@ -35,6 +35,9 @@
   _timer_callback
   # Callback from button presses in the UI outside the canvas
   _command
+  # Text-formatting for copying to clipboard
+  _get_text_format
+  _free_text_format
   # Game-saving and game-loading functions
   _get_save_file
   _free_save_file
--- a/emcc.c
+++ b/emcc.c
@@ -115,6 +115,8 @@
          bool shift, bool ctrl);
 void timer_callback(double tplus);
 void command(int n);
+char *get_text_format(void);
+void free_save_file(char *buffer);
 char *get_save_file(void);
 void free_save_file(char *buffer);
 void load_game(void);
@@ -878,6 +880,16 @@
         cfg_start(CFG_PREFS);
         break;
     }
+}
+
+char *get_text_format(void)
+{
+    return midend_text_format(me);
+}
+
+void free_text_format(char *buffer)
+{
+    sfree(buffer);
 }
 
 /* ----------------------------------------------------------------------
--- a/emccpre.js
+++ b/emccpre.js
@@ -670,6 +670,26 @@
         }
     });
 
+    // Handle "copy" actions.  Browsers don't reliably target the
+    // "copy" event at the canvas when it's focused.  Firefox 102
+    // targets the containing <div> while Chromium 114 targets the
+    // <body>.  So we catch the event at the document level and work
+    // out if it's relevant ourselves.
+    var get_text_format = Module.cwrap('get_text_format', 'number', []);
+    var free_text_format = Module.cwrap('free_text_format', 'void', ['number']);
+    document.addEventListener("copy", function(event) {
+        // Make sure the target is an ancestor of the canvas.  And if
+        // there's a selection assume the user wants to copy that and
+        // not the puzzle.
+        if (event.target.contains(onscreen_canvas) &&
+            window.getSelection().isCollapsed) {
+            var ptr = get_text_format();
+            event.clipboardData.setData('text/plain', UTF8ToString(ptr));
+            event.preventDefault();
+            free_text_format(ptr);
+        }
+    });
+
     // Event handler to fake :focus-within on browsers too old for
     // it (like KaiOS 2.5).  Browsers without :focus-within are also
     // too old for focusin/out events, so we have to use focus events