Implement new LFUN buffer-forall [<BUFFER-TYPE>] <LFUN-COMMAND>

This is a patch from Scott Kostyshak. See the thread here for some
background info:
http://thread.gmane.org/gmane.editors.lyx.devel/142300/focus=142362

src/FuncCode.h

@@ -452,6 +452,7 @@ enum FuncCode
 	// 350
 	LFUN_CLIPBOARD_PASTE_SIMPLE,	// tommaso, 20111028
 	LFUN_IPA_INSERT,                // spitz, 20120305
+	LFUN_BUFFER_FORALL,             // scottkostyshak, 20120720
 
 	LFUN_LASTACTION                 // end of the table
 };

src/LyXAction.cpp

@@ -3126,6 +3126,28 @@ void LyXAction::init()
  * \endvar
  */
 		{ LFUN_BUFFER_WRITE_AS, "buffer-write-as", ReadOnly, Buffer },
+/*!
+ * \var lyx::FuncCode lyx::LFUN_BUFFER_FORALL
+ * \li Action: Applies a command to all visible, hidden, or both types of buffers in the active window.
+ * \li Syntax: buffer-forall [<BUFFER-TYPE>] <LFUN-COMMAND>
+ * \li Params: <BUFFER-TYPE>: <visible|hidden|both default:> default: visible               
+               <LFUN-COMMAND>: The command that is to be applied to the buffers.
+ * \li Sample: Close all Notes in all visible documents: \n
+	           buffer-forall inset-forall Note inset-toggle close \n
+               Toggle change tracking on all documents: \n
+	           buffer-forall both changes-track \n
+               Toggle read-only for all visible documents: \n
+	           buffer-forall buffer-toggle-read-only \n
+               Show statistics for each document: \n
+	           buffer-forall both statistics \n
+               Activate the branch named "Solutions" in all visible documents: \n
+	           buffer-forall branch-activate Solutions \n
+               Export all visible documents to PDF (pdflatex): \n
+	           buffer-forall buffer-export pdf2 \n
+ * \li Origin: scottkostyshak, 20 Jul 2012
+ * \endvar
+ */
+		{ LFUN_BUFFER_FORALL, "buffer-forall", ReadOnly | Argument, Buffer },
 /*!
  * \var lyx::FuncCode lyx::LFUN_BUFFER_WRITE_ALL
  * \li Action: Save all changed documents.

src/frontends/qt4/GuiApplication.cpp

@@ -38,6 +38,7 @@
 #include "Font.h"
 #include "FuncRequest.h"
 #include "FuncStatus.h"
+#include "GuiWorkArea.h"
 #include "Intl.h"
 #include "KeyMap.h"
 #include "Language.h"
@@ -1077,6 +1078,15 @@ bool GuiApplication::getStatus(FuncRequest const & cmd, FuncStatus & flag) const
 		enable = true;
 		break;
 
+	case LFUN_BUFFER_FORALL: {
+		if (!currentView() || !currentView()->currentBufferView() || !&currentView()->currentBufferView()->buffer()) {
+			flag.message(from_utf8(N_("Command not allowed without any visible document in the active window")));
+			flag.setEnabled(false);
+		}
+		break;
+	}
+
+
 	default:
 		return false;
 	}
@@ -1592,6 +1602,63 @@ void GuiApplication::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 		break;
 	}
 
+	case LFUN_BUFFER_FORALL: {
+		GuiView * gv = currentView();
+		Buffer * const buf = &gv->currentBufferView()->buffer();
+
+		bool processVisible = true;
+		bool processHidden = false;
+		docstring msg = _("Applied the following command to all visible buffers in the active window: ");
+		string commandToRun = argument;
+		if (cmd.getArg(0) == "both") {
+			processHidden = true;
+			msg = _("Applied the following command to all visible and hidden buffers in the active window: ");
+			commandToRun = cmd.getLongArg(1);
+		} else if (cmd.getArg(0) == "visible") {
+			commandToRun = cmd.getLongArg(1);
+		} else if (cmd.getArg(0) == "hidden") {
+			processHidden = true;
+			processVisible = false;
+			commandToRun = cmd.getLongArg(1);
+			msg = _("Applied the following command to all hidden buffers in the active window: ");
+		}
+		FuncRequest const funcToRun = lyxaction.lookupFunc(commandToRun);
+		dr.setMessage(bformat(_("%1$s%2$s"), msg, from_utf8(commandToRun)));
+
+		Buffer * const last = theBufferList().last();
+		Buffer * b = theBufferList().first();
+		Buffer * nextBuf = 0;
+		// We cannot use a for loop as the buffer list cycles.
+		while (true) {
+			if (b != last)
+				nextBuf = theBufferList().next(b); //get next now bc LFUN might close current 
+
+			bool const hidden = !(gv && gv->workArea(*b));
+			if (hidden) {
+				if (processHidden) {
+					gv->setBuffer(b);
+					lyx::dispatch(funcToRun);
+					gv->currentWorkArea()->view().hideWorkArea(gv->currentWorkArea());
+				}
+			}
+
+			else {
+				if (processVisible) {
+					gv->setBuffer(b);
+					lyx::dispatch(funcToRun);
+				}
+			}
+
+			if (b == last)
+				break;
+			b = nextBuf;
+		}
+
+		if (theBufferList().isLoaded(buf)) //the LFUN might have closed buf
+			gv->setBuffer(buf);
+		break;
+	}
+
 	case LFUN_COMMAND_ALTERNATIVES: {
 		// argument contains ';'-terminated commands
 		string arg = argument;