From ef6460a4e9da4b5082fe908fa9ef489c7ed2d652 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Mon, 26 Oct 2015 23:16:09 +0100
Subject: [PATCH] unicode: copy to clipboard using execCommand

Fallback via temporary textarea for modern browsers (chrome 43+, ff 41+).

Code adapted from:
<http://stackoverflow.com/questions/400212/copy-in-js#answer-30810322>
---
 clipboard.js | 42 ++++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/clipboard.js b/clipboard.js
index cbf43d6..8ef21d1 100644
--- a/clipboard.js
+++ b/clipboard.js
@@ -5,29 +5,31 @@ function clipboardcopy(val) {
 		return window.clipboardData.setData('text', val);
 	}
 
-	if (netscape && netscape.security) {
-		// request access to XPCOM api
-		try {
-			netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
-		}
-		catch(e) {
-			if (copyhint)
-				alert('Cannot access clipboard.\nSet boolean signed.applets.codebase_principal_support in about:config');
-			copyhint = false;
-			return false;
-		}
+	if (document.queryCommandSupported('copy')) {
+		var textArea = document.createElement('textarea');
 
-		// use nsIClipboard interface
+		// minimise styling in case it is (briefly) rendered
+		textArea.style.position = 'fixed';
+		textArea.style.top = 0;
+		textArea.style.left = 0;
+		textArea.style.width = '2em';
+		textArea.style.height = '2em';
+		textArea.style.padding = 0;
+		textArea.style.border = 'none';
+		textArea.style.outline = 'none';
+		textArea.style.boxShadow = 'none';
+		textArea.style.background = 'transparent';
+
+		// temporarily add input field to copy text from
+		textArea.value = val;
+		document.body.appendChild(textArea);
 		try {
-			Components.classes['@mozilla.org/widget/clipboardhelper;1']
-				.getService(Components.interfaces.nsIClipboardHelper)
-				.copyString(val);
-			return true;
-		}
-		catch(e) {
-			alert('Copy failed');
-			return false;
+			textArea.select();
+			document.execCommand('copy');
+		} catch (e) {
+			console.log('could not copy "'+val+'" to clipboard');
 		}
+		document.body.removeChild(textArea);
 	}
 }
 
-- 
2.30.0