From f098e2fac8e90e8961769d7e72585ba2795f6ef5 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Fri, 15 Jul 2011 04:05:22 +0000
Subject: [PATCH] Add an optional Validate method to commands

Originally committed to SVN as r5459.
---
 aegisub/src/base_grid.cpp        | 22 ++------
 aegisub/src/base_grid.h          |  2 +-
 aegisub/src/command/app.cpp      | 12 ++++
 aegisub/src/command/audio.cpp    | 50 +++++++++++++----
 aegisub/src/command/command.h    | 11 ++++
 aegisub/src/command/edit.cpp     | 64 ++++++++++++++++++---
 aegisub/src/command/grid.cpp     | 14 ++++-
 aegisub/src/command/keyframe.cpp |  8 +++
 aegisub/src/command/subtitle.cpp | 28 ++++++++--
 aegisub/src/command/time.cpp     | 41 +++++++++++---
 aegisub/src/command/timecode.cpp |  8 +++
 aegisub/src/command/video.cpp    | 95 +++++++++++++++-----------------
 aegisub/src/frame_main.cpp       | 38 -------------
 aegisub/src/subs_grid.cpp        |  3 +-
 14 files changed, 252 insertions(+), 144 deletions(-)

diff --git a/aegisub/src/base_grid.cpp b/aegisub/src/base_grid.cpp
index d2278de66..ac91b1fb7 100644
--- a/aegisub/src/base_grid.cpp
+++ b/aegisub/src/base_grid.cpp
@@ -461,28 +461,14 @@ int BaseGrid::GetLastSelRow() const {
 
 
 /// @brief Gets all selected rows 
-/// @param[out] cont Is the selection contiguous, i.e. free from holes
 /// @return Array with indices of selected lines
 ///
-wxArrayInt BaseGrid::GetSelection(bool *cont) const {
-	int last = -1;
-	bool continuous = true;
-
-	std::set<int> sel_row_indices;
-
+wxArrayInt BaseGrid::GetSelection() const {
+	wxArrayInt res(selection.size());
 	for (Selection::const_iterator it = selection.begin(); it != selection.end(); ++it) {
-		sel_row_indices.insert(GetDialogueIndex(*it));
+		res.push_back(GetDialogueIndex(*it));
 	}
-
-	// Iterating the int set yields a sorted list
-	wxArrayInt res;
-	for (std::set<int>::iterator it = sel_row_indices.begin(); it != sel_row_indices.end(); ++it) {
-		res.Add(*it);
-		if (last != -1 && *it != last+1) continuous = false;
-		last = *it;
-	}
-
-	if (cont) *cont = continuous;
+	std::sort(res.begin(), res.end());
 	return res;
 }
 
diff --git a/aegisub/src/base_grid.h b/aegisub/src/base_grid.h
index 1e97779d4..ccb645a3c 100644
--- a/aegisub/src/base_grid.h
+++ b/aegisub/src/base_grid.h
@@ -158,7 +158,7 @@ public:
 	int GetFirstSelRow() const;
 	int GetLastSelRow() const;
 	void SelectVisible();
-	wxArrayInt GetSelection(bool *continuous=NULL) const;
+	wxArrayInt GetSelection() const;
 
 	void ClearMaps();
 	/// @brief Update the row <-> AssDialogue mappings
diff --git a/aegisub/src/command/app.cpp b/aegisub/src/command/app.cpp
index 52a2dbb46..1b9f443ed 100644
--- a/aegisub/src/command/app.cpp
+++ b/aegisub/src/command/app.cpp
@@ -85,6 +85,10 @@ struct app_display_audio_subs : public Command {
 	void operator()(agi::Context *c) {
 		wxGetApp().frame->SetDisplayMode(0,1);
 	}
+
+	bool Validate(const agi::Context *c) {
+		return c->audioController->IsAudioOpen();
+	}
 };
 
 
@@ -98,6 +102,10 @@ struct app_display_full : public Command {
 	void operator()(agi::Context *c) {
 		wxGetApp().frame->SetDisplayMode(1,1);
 	}
+
+	bool Validate(const agi::Context *c) {
+		return c->audioController->IsAudioOpen() && c->videoController->IsLoaded() && !c->detachedVideo;
+	}
 };
 
 
@@ -124,6 +132,10 @@ struct app_display_video_subs : public Command {
 	void operator()(agi::Context *c) {
 		wxGetApp().frame->SetDisplayMode(1,0);
 	}
+
+	bool Validate(const agi::Context *c) {
+		return c->videoController->IsLoaded() && !c->detachedVideo;
+	}
 };
 
 
diff --git a/aegisub/src/command/audio.cpp b/aegisub/src/command/audio.cpp
index 675ac7511..2d595adf5 100644
--- a/aegisub/src/command/audio.cpp
+++ b/aegisub/src/command/audio.cpp
@@ -49,18 +49,25 @@
 #include "../audio_timing.h"
 #include "../compat.h"
 #include "../include/aegisub/context.h"
-#include "../selection_controller.h"
 #include "../main.h"
-
-typedef SelectionController<AssDialogue>::Selection Selection;
+#include "../selection_controller.h"
+#include "../video_context.h"
 
 namespace {
+	typedef SelectionController<AssDialogue>::Selection Selection;
 	using cmd::Command;
+
+	struct validate_audio_open : public Command {
+		bool Validate(const agi::Context *c) {
+			return c->audioController->IsAudioOpen();
+		}
+	};
+
 /// @defgroup cmd-audio Audio commands.
 /// @{
 
 /// Closes the currently open audio file.
-struct audio_close : public Command {
+struct audio_close : public validate_audio_open {
 	CMD_NAME("audio/close")
 	STR_MENU("&Close Audio")
 	STR_DISP("Close Audio")
@@ -126,6 +133,10 @@ struct audio_open_video : public Command {
 	STR_DISP("Open Audio from Video")
 	STR_HELP("Opens the audio from the current video file.")
 
+	bool Validate(const agi::Context *c) {
+		return c->videoController->IsLoaded();
+	}
+
 	void operator()(agi::Context *c) {
 		c->audioController->OpenAudio(_T("audio-video:cache"));
 	}
@@ -176,11 +187,12 @@ struct audio_save_clip : public Command {
 };
 
 /// Play the current audio selection
-struct audio_play_selection : public Command {
+struct audio_play_selection : public validate_audio_open {
 	CMD_NAME("audio/play/selection")
 	STR_MENU("Play audio selection")
 	STR_DISP("Play audio selection")
 	STR_HELP("Play selection")
+
 	void operator()(agi::Context *c) {
 		c->audioController->PlayPrimaryRange();
 	}
@@ -192,17 +204,23 @@ struct audio_stop : public Command {
 	STR_MENU("Stop playing")
 	STR_DISP("Stop playing")
 	STR_HELP("Stop")
+
+	bool Validate(const agi::Context *c) {
+		return c->audioController->IsPlaying();
+	}
+
 	void operator()(agi::Context *c) {
 		c->audioController->Stop();
 	}
 };
 
 /// Play 500 ms before the selected audio range
-struct audio_play_before : public Command {
+struct audio_play_before : public validate_audio_open {
 	CMD_NAME("audio/play/selection/before")
 	STR_MENU("Play 500 ms before selection")
 	STR_DISP("Play 500 ms before selection")
 	STR_HELP("Play 500 ms before selection")
+
 	void operator()(agi::Context *c) {
 		SampleRange times(c->audioController->GetPrimaryPlaybackRange());
 		c->audioController->PlayRange(SampleRange(
@@ -212,11 +230,12 @@ struct audio_play_before : public Command {
 };
 
 /// Play 500 ms after the selected audio range
-struct audio_play_after : public Command {
+struct audio_play_after : public validate_audio_open {
 	CMD_NAME("audio/play/selection/after")
 	STR_MENU("Play 500 ms after selection")
 	STR_DISP("Play 500 ms after selection")
 	STR_HELP("Play 500 ms after selection")
+
 	void operator()(agi::Context *c) {
 		SampleRange times(c->audioController->GetPrimaryPlaybackRange());
 		c->audioController->PlayRange(SampleRange(
@@ -226,11 +245,12 @@ struct audio_play_after : public Command {
 };
 
 /// Play from the beginning of the audio range to the end of the file
-struct audio_play_end : public Command {
+struct audio_play_end : public validate_audio_open {
 	CMD_NAME("audio/play/selection/end")
 	STR_MENU("Play last 500 ms of selection")
 	STR_DISP("Play last 500 ms of selection")
 	STR_HELP("Play last 500 ms of selection")
+
 	void operator()(agi::Context *c) {
 		SampleRange times(c->audioController->GetPrimaryPlaybackRange());
 		c->audioController->PlayRange(SampleRange(
@@ -242,11 +262,12 @@ struct audio_play_end : public Command {
 };
 
 /// Play the first 500 ms of the audio range
-struct audio_play_begin : public Command {
+struct audio_play_begin : public validate_audio_open {
 	CMD_NAME("audio/play/selection/begin")
 	STR_MENU("Play first 500 ms of selection")
 	STR_DISP("Play first 500 ms of selection")
 	STR_HELP("Play first 500 ms of selection")
+
 	void operator()(agi::Context *c) {
 		SampleRange times(c->audioController->GetPrimaryPlaybackRange());
 		c->audioController->PlayRange(SampleRange(
@@ -258,11 +279,12 @@ struct audio_play_begin : public Command {
 };
 
 /// Play the last 500 ms of the audio range
-struct audio_play_to_end : public Command {
+struct audio_play_to_end : public validate_audio_open {
 	CMD_NAME("audio/play/to_end")
 	STR_MENU("Play from selection start to end of file")
 	STR_DISP("Play from selection start to end of file")
 	STR_HELP("Play from selection start to end of file")
+
 	void operator()(agi::Context *c) {
 		c->audioController->PlayToEnd(c->audioController->GetPrimaryPlaybackRange().begin());
 	}
@@ -275,6 +297,7 @@ struct audio_commit : public Command {
 	STR_MENU("Commit")
 	STR_DISP("Commit")
 	STR_HELP("Commit")
+
 	void operator()(agi::Context *c) {
 		c->audioController->GetTimingController()->Commit();
 	}
@@ -286,6 +309,7 @@ struct audio_go_to : public Command {
 	STR_MENU("Go to selection")
 	STR_DISP("Go to selection")
 	STR_HELP("Go to selection")
+
 	void operator()(agi::Context *c) {
 		//if (c->audioController->GetTimingController())
 			//audioDisplay->ScrollSampleRangeInView(c->audioController->GetTimingController()->GetIdealVisibleSampleRange());
@@ -302,6 +326,7 @@ struct audio_autoscroll : public Command {
 	STR_MENU("Auto scrolls audio display to selected line")
 	STR_DISP("Auto scrolls audio display to selected line")
 	STR_HELP("Auto scrolls audio display to selected line")
+
 	void operator()(agi::Context *c) {
 		toggle("Audio/Auto/Scroll");
 	}
@@ -313,6 +338,7 @@ struct audio_autocommit : public Command {
 	STR_MENU("Automatically commit all changes")
 	STR_DISP("Automatically commit all changes")
 	STR_HELP("Automatically commit all changes")
+
 	void operator()(agi::Context *c) {
 		toggle("Audio/Auto/Commit");
 	}
@@ -324,6 +350,7 @@ struct audio_autonext : public Command {
 	STR_MENU("Auto goes to next line on commit")
 	STR_DISP("Auto goes to next line on commit")
 	STR_HELP("Auto goes to next line on commit")
+
 	void operator()(agi::Context *c) {
 		toggle("Audio/Next Line on Commit");
 	}
@@ -335,6 +362,7 @@ struct audio_vertical_link : public Command {
 	STR_MENU("Link vertical zoom and volume sliders")
 	STR_DISP("Link vertical zoom and volume sliders")
 	STR_HELP("Link vertical zoom and volume sliders")
+
 	void operator()(agi::Context *c) {
 		toggle("Audio/Link");
 	}
@@ -353,8 +381,10 @@ namespace cmd {
 		reg(new audio_commit);
 		reg(new audio_go_to);
 		reg(new audio_open);
+#if _DEBUG
 		reg(new audio_open_blank);
 		reg(new audio_open_noise);
+#endif
 		reg(new audio_open_video);
 		reg(new audio_play_after);
 		reg(new audio_play_before);
diff --git a/aegisub/src/command/command.h b/aegisub/src/command/command.h
index 5cfdd8da2..e82adb5da 100644
--- a/aegisub/src/command/command.h
+++ b/aegisub/src/command/command.h
@@ -66,6 +66,17 @@ namespace cmd {
 		/// Command function
 		virtual void operator()(agi::Context *c)=0;
 
+		/// Check whether or not it makes sense to call this command at this time
+		/// @param c Project context
+		///
+		/// This function should be very fast, as it is called whenever a menu
+		/// containing this command is opened and is called periodically for
+		/// any commands used in a toolbar
+		///
+		/// Note that it is still legal to call commands when this returns
+		/// false. In this situation, commands should do nothing.
+		virtual bool Validate(const agi::Context *c) { return true; }
+
 		/// Destructor
 		virtual ~Command() { };
 	};
diff --git a/aegisub/src/command/edit.cpp b/aegisub/src/command/edit.cpp
index bc668e699..13b28f098 100644
--- a/aegisub/src/command/edit.cpp
+++ b/aegisub/src/command/edit.cpp
@@ -58,8 +58,20 @@ namespace {
 /// @defgroup cmd-edit Editing commands.
 /// @{
 
+struct validate_sel_nonempty : public Command {
+	bool Validate(const agi::Context *c) {
+		return c->selectionController->GetSelectedSet().size() > 0;
+	}
+};
+
+struct validate_sel_multiple : public Command {
+	bool Validate(const agi::Context *c) {
+		return c->selectionController->GetSelectedSet().size() > 1;
+	}
+};
+
 /// Copy subtitles.
-struct edit_line_copy : public Command {
+struct edit_line_copy : public validate_sel_nonempty {
 	CMD_NAME("edit/line/copy")
 	STR_MENU("Copy Lines")
 	STR_DISP("Copy Lines")
@@ -76,7 +88,7 @@ struct edit_line_copy : public Command {
 
 
 /// Cut subtitles.
-struct edit_line_cut: public Command {
+struct edit_line_cut: public validate_sel_nonempty {
 	CMD_NAME("edit/line/cut")
 	STR_MENU("Cut Lines")
 	STR_DISP("Cut Lines")
@@ -93,7 +105,7 @@ struct edit_line_cut: public Command {
 
 
 /// Delete currently selected lines.
-struct edit_line_delete : public Command {
+struct edit_line_delete : public validate_sel_nonempty {
 	CMD_NAME("edit/line/delete")
 	STR_MENU("Delete Lines")
 	STR_DISP("Delete Lines")
@@ -106,7 +118,7 @@ struct edit_line_delete : public Command {
 
 
 /// Duplicate the selected lines.
-struct edit_line_duplicate : public Command {
+struct edit_line_duplicate : public validate_sel_nonempty {
 	CMD_NAME("edit/line/duplicate")
 	STR_MENU("&Duplicate Lines")
 	STR_DISP("Duplicate Lines")
@@ -126,6 +138,10 @@ struct edit_line_duplicate_shift : public Command {
 	STR_DISP("Duplicate and Shift by 1 Frame")
 	STR_HELP("Duplicate lines and shift by one frame.")
 
+	bool Validate(const agi::Context *c) {
+		return !c->selectionController->GetSelectedSet().empty() && c->videoController->IsLoaded();
+	}
+
 	void operator()(agi::Context *c) {
 		wxArrayInt sels = c->subsGrid->GetSelection();
 		c->subsGrid->DuplicateLines(sels.front(), sels.back(), true);
@@ -174,7 +190,7 @@ static void combine_concat(AssDialogue *first, AssDialogue *second) {
 static void combine_drop(AssDialogue *, AssDialogue *) { }
 
 /// Joins selected lines in a single one, as karaoke.
-struct edit_line_join_as_karaoke : public Command {
+struct edit_line_join_as_karaoke : public validate_sel_multiple {
 	CMD_NAME("edit/line/join/as_karaoke")
 	STR_MENU("As &Karaoke")
 	STR_DISP("As Karaoke")
@@ -187,7 +203,7 @@ struct edit_line_join_as_karaoke : public Command {
 
 
 /// Joins selected lines in a single one, concatenating text together.
-struct edit_line_join_concatenate : public Command {
+struct edit_line_join_concatenate : public validate_sel_multiple {
 	CMD_NAME("edit/line/join/concatenate")
 	STR_MENU("&Concatenate")
 	STR_DISP("Concatenate")
@@ -200,7 +216,7 @@ struct edit_line_join_concatenate : public Command {
 
 
 /// Joins selected lines in a single one, keeping text of first and discarding remaining.
-struct edit_line_join_keep_first : public Command {
+struct edit_line_join_keep_first : public validate_sel_multiple {
 	CMD_NAME("edit/line/join/keep_first")
 	STR_MENU("Keep &First")
 	STR_DISP("Keep First")
@@ -219,6 +235,15 @@ struct edit_line_paste : public Command {
 	STR_DISP("Paste Lines")
 	STR_HELP("Paste subtitles.")
 
+	bool Validate(const agi::Context *c) {
+		if (wxTheClipboard->Open()) {
+			bool can_paste = wxTheClipboard->IsSupported(wxDF_TEXT);
+			wxTheClipboard->Close();
+			return can_paste;
+		}
+		return false;
+	}
+
 	void operator()(agi::Context *c) {
 		if (c->parent->FindFocus() == c->editBox->TextEdit) {
 			c->editBox->TextEdit->Paste();
@@ -236,6 +261,15 @@ struct edit_line_paste_over : public Command {
 	STR_DISP("Paste Lines Over")
 	STR_HELP("Paste subtitles over others.")
 
+	bool Validate(const agi::Context *c) {
+		if (wxTheClipboard->Open()) {
+			bool can_paste = wxTheClipboard->IsSupported(wxDF_TEXT);
+			wxTheClipboard->Close();
+			return can_paste && c->selectionController->GetSelectedSet().size();
+		}
+		return false;
+	}
+
 	void operator()(agi::Context *c) {
 		c->subsGrid->PasteLines(c->subsGrid->GetFirstSelRow(),true);
 	}
@@ -243,7 +277,7 @@ struct edit_line_paste_over : public Command {
 
 
 /// Recombine subtitles when they have been split and merged.
-struct edit_line_recombine : public Command {
+struct edit_line_recombine : public validate_sel_multiple {
 	CMD_NAME("edit/line/recombine")
 	STR_MENU("Recombine Lines")
 	STR_DISP("Recombine Lines")
@@ -256,7 +290,7 @@ struct edit_line_recombine : public Command {
 
 
 /// Uses karaoke timing to split line into multiple smaller lines.
-struct edit_line_split_by_karaoke : public Command {
+struct edit_line_split_by_karaoke : public validate_sel_nonempty {
 	CMD_NAME("edit/line/split/by_karaoke")
 	STR_MENU("Split Lines (by karaoke)")
 	STR_DISP("Split Lines (by karaoke)")
@@ -284,6 +318,10 @@ struct edit_line_swap : public Command {
 	STR_DISP("Swap Lines")
 	STR_HELP("Swaps the two selected lines.")
 
+	bool Validate(const agi::Context *c) {
+		return c->selectionController->GetSelectedSet().size() == 2;
+	}
+
 	void operator()(agi::Context *c) {
 		SelectionController<AssDialogue>::Selection sel = c->selectionController->GetSelectedSet();
 		if (sel.size() == 2) {
@@ -305,6 +343,10 @@ struct edit_redo : public Command {
 	STR_DISP("Redo")
 	STR_HELP("Redoes last action.")
 
+	bool Validate(const agi::Context *c) {
+		return !c->ass->IsRedoStackEmpty();
+	}
+
 	void operator()(agi::Context *c) {
 		c->videoController->Stop();
 		c->ass->Redo();
@@ -333,6 +375,10 @@ struct edit_undo : public Command {
 	STR_DISP("Undo")
 	STR_HELP("Undoes last action.")
 
+	bool Validate(const agi::Context *c) {
+		return !c->ass->IsUndoStackEmpty();
+	}
+
 	void operator()(agi::Context *c) {
 		c->videoController->Stop();
 		c->ass->Undo();
diff --git a/aegisub/src/command/grid.cpp b/aegisub/src/command/grid.cpp
index b12c2d63a..32c01ff88 100644
--- a/aegisub/src/command/grid.cpp
+++ b/aegisub/src/command/grid.cpp
@@ -167,12 +167,16 @@ struct grid_swap_up : public Command {
 	STR_DISP("Move line up")
 	STR_HELP("Move the selected line up one row")
 
+	bool Validate(agi::Context *c) {
+		return c->selectionController->GetActiveLine() != 0;
+	}
+
 	void operator()(agi::Context *c) {
 		if (AssDialogue *line = c->selectionController->GetActiveLine()) {
 			if (move_one(c->ass->Line.rbegin(), c->ass->Line.rend(), line))
-				/// todo Maybe add COMMIT_ORDER, as the grid is the only thing
-				///      that needs to care about this
-				///      Probably not worth it
+				/// @todo Maybe add COMMIT_ORDER, as the grid is the only thing
+				///       that needs to care about this
+				///       Probably not worth it
 				c->ass->Commit(_("swap lines"), AssFile::COMMIT_FULL);
 		}
 	}
@@ -185,6 +189,10 @@ struct grid_swap_down : public Command {
 		STR_DISP("Move line down")
 		STR_HELP("Move the selected line down one row")
 
+	bool Validate(agi::Context *c) {
+		return c->selectionController->GetActiveLine() != 0;
+	}
+
 		void operator()(agi::Context *c) {
 			if (AssDialogue *line = c->selectionController->GetActiveLine()) {
 				if (move_one(c->ass->Line.begin(), c->ass->Line.end(), line))
diff --git a/aegisub/src/command/keyframe.cpp b/aegisub/src/command/keyframe.cpp
index af1455168..041faebbd 100644
--- a/aegisub/src/command/keyframe.cpp
+++ b/aegisub/src/command/keyframe.cpp
@@ -62,6 +62,10 @@ struct keyframe_close : public Command {
 	STR_DISP("Close Keyframes")
 	STR_HELP("Closes the currently open keyframes list.")
 
+	bool Validate(const agi::Context *c) {
+		return c->videoController->OverKeyFramesLoaded();
+	}
+
 	void operator()(agi::Context *c) {
 		c->videoController->CloseKeyframes();
 	}
@@ -99,6 +103,10 @@ struct keyframe_save : public Command {
 	STR_DISP("Save Keyframes")
 	STR_HELP("Saves the current keyframe list.")
 
+	bool Validate(const agi::Context *c) {
+		return c->videoController->KeyFramesLoaded();
+	}
+
 	void operator()(agi::Context *c) {
 		wxString path = lagi_wxString(OPT_GET("Path/Last/Keyframes")->GetString());
 		wxString filename = wxFileSelector(_T("Select the Keyframes file to open"),path,_T(""),_T("*.key.txt"),_T("Text files (*.txt)|*.txt"),wxFD_OVERWRITE_PROMPT | wxFD_SAVE);
diff --git a/aegisub/src/command/subtitle.cpp b/aegisub/src/command/subtitle.cpp
index 10f0cd421..30df21e91 100644
--- a/aegisub/src/command/subtitle.cpp
+++ b/aegisub/src/command/subtitle.cpp
@@ -67,6 +67,18 @@ namespace {
 /// @defgroup cmd-subtitle Subtitle commands.
 /// @{
 
+struct validate_nonempty_selection : public Command {
+	bool Validate(const agi::Context *c) {
+		return !c->selectionController->GetSelectedSet().empty();
+	}
+};
+
+struct validate_nonempty_selection_video_loaded : public Command {
+	bool Validate(const agi::Context *c) {
+		return c->videoController->IsLoaded() && !c->selectionController->GetSelectedSet().empty();
+	}
+};
+
 /// Open the attachment list.
 struct subtitle_attachment : public Command {
 	CMD_NAME("subtitle/attachment")
@@ -127,7 +139,7 @@ static void insert_subtitle_at_video(agi::Context *c, bool after) {
 }
 
 /// Inserts a line after current.
-struct subtitle_insert_after : public Command {
+struct subtitle_insert_after : public validate_nonempty_selection {
 	CMD_NAME("subtitle/insert/after")
 	STR_MENU("&After Current")
 	STR_DISP("After Current")
@@ -161,7 +173,7 @@ struct subtitle_insert_after : public Command {
 };
 
 /// Inserts a line after current, starting at video time.
-struct subtitle_insert_after_videotime : public Command {
+struct subtitle_insert_after_videotime : public validate_nonempty_selection_video_loaded {
 	CMD_NAME("subtitle/insert/after/videotime")
 	STR_MENU("After Current, at Video Time")
 	STR_DISP("After Current, at Video Time")
@@ -174,7 +186,7 @@ struct subtitle_insert_after_videotime : public Command {
 
 
 /// Inserts a line before current.
-struct subtitle_insert_before : public Command {
+struct subtitle_insert_before : public validate_nonempty_selection {
 	CMD_NAME("subtitle/insert/before")
 	STR_MENU("&Before Current")
 	STR_DISP("Before Current")
@@ -211,7 +223,7 @@ struct subtitle_insert_before : public Command {
 
 
 /// Inserts a line before current, starting at video time.
-struct subtitle_insert_before_videotime : public Command {
+struct subtitle_insert_before_videotime : public validate_nonempty_selection_video_loaded {
 	CMD_NAME("subtitle/insert/before/videotime")
 	STR_MENU("Before Current, at Video Time")
 	STR_DISP("Before Current, at Video Time")
@@ -286,6 +298,10 @@ struct subtitle_open_video : public Command {
 	void operator()(agi::Context *c) {
 		wxGetApp().frame->LoadSubtitles(c->videoController->videoName, "binary");
 	}
+
+	bool Validate(const agi::Context *c) {
+		return c->videoController->IsLoaded() && c->videoController->HasSubtitles();
+	}
 };
 
 
@@ -377,6 +393,10 @@ struct subtitle_select_visible : public Command {
 		c->videoController->Stop();
 		c->subsGrid->SelectVisible();
 	}
+
+	bool Validate(agi::Context *c) {
+		return c->videoController->IsLoaded();
+	}
 };
 
 
diff --git a/aegisub/src/command/time.cpp b/aegisub/src/command/time.cpp
index 9b5f4a19d..d6b61ba07 100644
--- a/aegisub/src/command/time.cpp
+++ b/aegisub/src/command/time.cpp
@@ -57,11 +57,38 @@
 
 namespace {
 	using cmd::Command;
+
+	struct validate_video_loaded : public Command {
+		bool Validate(const agi::Context *c) {
+			return c->videoController->IsLoaded();
+		}
+	};
+
+	struct validate_adjoinable : public Command {
+		bool Validate(const agi::Context *c) {
+			SelectionController<AssDialogue>::Selection sel = c->selectionController->GetSelectedSet();
+			if (sel.size() < 2) return false;
+
+			bool found = false;
+			for (entryIter it = c->ass->Line.begin(); it != c->ass->Line.end(); ++it) {
+				AssDialogue *diag = dynamic_cast<AssDialogue*>(*it);
+				if (!diag) continue;
+				if (sel.count(diag)) {
+					found = true;
+				}
+				else if (found) {
+					return false;
+				}
+			}
+			return true;
+		}
+	};
+
 /// @defgroup cmd-time Time manipulation commands.
 /// @{
 
 /// Changes times of subs so end times begin on next's start time.
-struct time_continuous_end : public Command {
+struct time_continuous_end : public validate_adjoinable {
 	CMD_NAME("time/continuous/end")
 	STR_MENU("Change &End")
 	STR_DISP("Change End")
@@ -75,7 +102,7 @@ struct time_continuous_end : public Command {
 
 
 /// Changes times of subs so start times begin on previous's end time.
-struct time_continuous_start : public Command {
+struct time_continuous_start : public validate_adjoinable {
 	CMD_NAME("time/continuous/start")
 	STR_MENU("Change &Start")
 	STR_DISP("Change Start")
@@ -90,7 +117,7 @@ struct time_continuous_start : public Command {
 
 
 /// Shift selection so first selected line starts at current frame.
-struct time_frame_current : public Command {
+struct time_frame_current : public validate_video_loaded {
 	CMD_NAME("time/frame/current")
 	STR_MENU("Shift to Current Frame")
 	STR_DISP("Shift to Current Frame")
@@ -139,7 +166,7 @@ struct time_shift : public Command {
 
 
 /// Set end of selected subtitles to current video frame.
-struct time_snap_end_video : public Command {
+struct time_snap_end_video : public validate_video_loaded {
 	CMD_NAME("time/snap/end_video")
 	STR_MENU("Snap End to Video")
 	STR_DISP("Snap End to Video")
@@ -152,7 +179,7 @@ struct time_snap_end_video : public Command {
 
 
 /// Shift selected subtitles so first selected starts at this frame.
-struct time_snap_frame : public Command {
+struct time_snap_frame : public validate_video_loaded {
 	CMD_NAME("time/snap/frame")
 	STR_MENU("Shift Subtitles to Frame")
 	STR_DISP("Shift Subtitles to Frame")
@@ -181,7 +208,7 @@ struct time_snap_frame : public Command {
 
 
 /// Set start and end of subtitles to the keyframes around current video frame.
-struct time_snap_scene : public Command {
+struct time_snap_scene : public validate_video_loaded {
 	CMD_NAME("time/snap/scene")
 	STR_MENU("Snap to Scene")
 	STR_DISP("Snap to Scene")
@@ -262,7 +289,7 @@ struct time_add_lead_out : public Command {
 
 
 /// Set start of selected subtitles to current video frame.
-struct time_snap_start_video : public Command {
+struct time_snap_start_video : public validate_video_loaded {
 	CMD_NAME("time/snap/start_video")
 	STR_MENU("Snap Start to Video")
 	STR_DISP("Snap Start to Video")
diff --git a/aegisub/src/command/timecode.cpp b/aegisub/src/command/timecode.cpp
index f8b4e00f3..f0f1dd375 100644
--- a/aegisub/src/command/timecode.cpp
+++ b/aegisub/src/command/timecode.cpp
@@ -62,6 +62,10 @@ struct timecode_close : public Command {
 	STR_DISP("Close Timecodes File")
 	STR_HELP("Closes the currently open timecodes file.")
 
+	bool Validate(const agi::Context *c) {
+		return c->videoController->OverTimecodesLoaded();
+	}
+
 	void operator()(agi::Context *c) {
 		c->videoController->CloseTimecodes();
 	}
@@ -94,6 +98,10 @@ struct timecode_save : public Command {
 	STR_DISP("Save Timecodes File")
 	STR_HELP("Saves a VFR timecodes v2 file.")
 
+	bool Validate(const agi::Context *c) {
+		return c->videoController->TimecodesLoaded();
+	}
+
 	void operator()(agi::Context *c) {
 		wxString path = lagi_wxString(OPT_GET("Path/Last/Timecodes")->GetString());
 		wxString str = wxString(_("All Supported Types")) + _T("(*.txt)|*.txt|") + _("All Files") + _T(" (*.*)|*.*");
diff --git a/aegisub/src/command/video.cpp b/aegisub/src/command/video.cpp
index 5d4f0b4e9..6f7b69b6a 100644
--- a/aegisub/src/command/video.cpp
+++ b/aegisub/src/command/video.cpp
@@ -63,24 +63,34 @@ namespace {
 /// @defgroup cmd-video Video commands.
 /// @{
 
+struct validator_video_loaded : public Command {
+	bool Validate(const agi::Context *c) {
+		return c->videoController->IsLoaded();
+	}
+};
+
+struct validator_video_attached : public Command {
+	bool Validate(const agi::Context *c) {
+		return c->videoController->IsLoaded() && !c->detachedVideo;
+	}
+};
 
 /// Forces video to 2.35 aspect ratio.
-struct video_aspect_cinematic : public Command {
+struct video_aspect_cinematic : public validator_video_attached {
 	CMD_NAME("video/aspect/cinematic")
 	STR_MENU("&Cinematic (2.35)")
 	STR_DISP("Cinematic (235)")
 	STR_HELP("Forces video to 2.35 aspect ratio.")
 
 	void operator()(agi::Context *c) {
-	c->videoController->Stop();
-	c->videoController->SetAspectRatio(3);
-	wxGetApp().frame->SetDisplayMode(1,-1);
+		c->videoController->Stop();
+		c->videoController->SetAspectRatio(3);
+		wxGetApp().frame->SetDisplayMode(1,-1);
 	}
 };
 
-
 /// Forces video to a custom aspect ratio.
-struct video_aspect_custom : public Command {
+struct video_aspect_custom : public validator_video_attached {
 	CMD_NAME("video/aspect/custom")
 	STR_MENU("Custom..")
 	STR_DISP("Custom")
@@ -134,10 +144,8 @@ struct video_aspect_custom : public Command {
 	}
 };
 
-
-
 /// Leave video on original aspect ratio.
-struct video_aspect_default : public Command {
+struct video_aspect_default : public validator_video_attached {
 	CMD_NAME("video/aspect/default")
 	STR_MENU("&Default")
 	STR_DISP("Default")
@@ -150,10 +158,8 @@ struct video_aspect_default : public Command {
 	}
 };
 
-
-
 /// Forces video to 4:3 aspect ratio.
-struct video_aspect_full : public Command {
+struct video_aspect_full : public validator_video_attached {
 	CMD_NAME("video/aspect/full")
 	STR_MENU("&Fullscreen (4:3)")
 	STR_DISP("Fullscreen (4:3)")
@@ -166,9 +172,8 @@ struct video_aspect_full : public Command {
 	}
 };
 
-
 /// Forces video to 16:9 aspect ratio.
-struct video_aspect_wide : public Command {
+struct video_aspect_wide : public validator_video_attached {
 	CMD_NAME("video/aspect/wide")
 	STR_MENU("&Widescreen (16:9)")
 	STR_DISP("Widescreen (16:9)")
@@ -181,9 +186,8 @@ struct video_aspect_wide : public Command {
 	}
 };
 
-
 /// Closes the currently open video file.
-struct video_close : public Command {
+struct video_close : public validator_video_loaded {
 	CMD_NAME("video/close")
 	STR_MENU("&Close Video")
 	STR_DISP("Close Video")
@@ -194,10 +198,8 @@ struct video_close : public Command {
 	}
 };
 
-
-
 /// Detach video, displaying it in a separate Window.
-struct video_detach : public Command {
+struct video_detach : public validator_video_loaded {
 	CMD_NAME("video/detach")
 	STR_MENU("Detach Video")
 	STR_DISP("Detach Video")
@@ -208,9 +210,8 @@ struct video_detach : public Command {
 	}
 };
 
-
 /// Shows video details.
-struct video_details : public Command {
+struct video_details : public validator_video_loaded {
 	CMD_NAME("video/details")
 	STR_MENU("Show Video Details..")
 	STR_DISP("Show Video Details")
@@ -222,9 +223,8 @@ struct video_details : public Command {
 	}
 };
 
-
 /// 
-struct video_focus_seek : public Command {
+struct video_focus_seek : public validator_video_loaded {
 	CMD_NAME("video/focus_seek")
 	STR_MENU("XXX: no idea")
 	STR_DISP("XXX: no idea")
@@ -242,9 +242,8 @@ struct video_focus_seek : public Command {
 	}
 };
 
-
 /// Seek to the next frame.
-struct video_frame_next : public Command {
+struct video_frame_next : public validator_video_loaded {
 	CMD_NAME("video/frame/next")
 	STR_MENU("Next Frame")
 	STR_DISP("Next Frame")
@@ -256,7 +255,7 @@ struct video_frame_next : public Command {
 };
 
 /// Seek to the next subtitle boundary.
-struct video_frame_next_boundary : public Command {
+struct video_frame_next_boundary : public validator_video_loaded {
 	CMD_NAME("video/frame/next/boundary")
 	STR_MENU("Next Boundary")
 	STR_DISP("Next Boundary")
@@ -286,7 +285,7 @@ struct video_frame_next_boundary : public Command {
 };
 
 /// Seek to the next keyframe.
-struct video_frame_next_keyframe : public Command {
+struct video_frame_next_keyframe : public validator_video_loaded {
 	CMD_NAME("video/frame/next/keyframe")
 	STR_MENU("Next Keyframe")
 	STR_DISP("Next Keyframe")
@@ -302,7 +301,7 @@ struct video_frame_next_keyframe : public Command {
 };
 
 /// Fast jump forward
-struct video_frame_next_large : public Command {
+struct video_frame_next_large : public validator_video_loaded {
 	CMD_NAME("video/frame/next/large")
 	STR_MENU("Fast jump forward")
 	STR_DISP("Fast jump forward")
@@ -316,7 +315,7 @@ struct video_frame_next_large : public Command {
 };
 
 /// Seek to the previous frame.
-struct video_frame_prev : public Command {
+struct video_frame_prev : public validator_video_loaded {
 	CMD_NAME("video/frame/prev")
 	STR_MENU("Previous Frame")
 	STR_DISP("Previous Frame")
@@ -328,7 +327,7 @@ struct video_frame_prev : public Command {
 };
 
 /// Seek to the previous subtitle boundary.
-struct video_frame_prev_boundary : public Command {
+struct video_frame_prev_boundary : public validator_video_loaded {
 	CMD_NAME("video/frame/prev/boundary")
 	STR_MENU("Previous Boundary")
 	STR_DISP("Previous Boundary")
@@ -358,7 +357,7 @@ struct video_frame_prev_boundary : public Command {
 };
 
 /// Seek to the previous keyframe.
-struct video_frame_prev_keyframe : public Command {
+struct video_frame_prev_keyframe : public validator_video_loaded {
 	CMD_NAME("video/frame/prev/keyframe")
 	STR_MENU("Previous Keyframe")
 	STR_DISP("Previous Keyframe")
@@ -377,7 +376,7 @@ struct video_frame_prev_keyframe : public Command {
 };
 
 /// Fast jump backwards
-struct video_frame_prev_large : public Command {
+struct video_frame_prev_large : public validator_video_loaded {
 	CMD_NAME("video/frame/prev/large")
 	STR_MENU("Fast jump backwards")
 	STR_DISP("Fast jump backwards")
@@ -391,7 +390,7 @@ struct video_frame_prev_large : public Command {
 };
 
 /// Jump to frame or time.
-struct video_jump : public Command {
+struct video_jump : public validator_video_loaded {
 	CMD_NAME("video/jump")
 	STR_MENU("&Jump to..")
 	STR_DISP("Jump to")
@@ -406,9 +405,8 @@ struct video_jump : public Command {
 	}
 };
 
-
 /// Jumps the video to the end frame of current subtitle.
-struct video_jump_end : public Command {
+struct video_jump_end : public validator_video_loaded {
 	CMD_NAME("video/jump/end")
 	STR_MENU("Jump Video to End")
 	STR_DISP("Jump Video to End")
@@ -419,9 +417,8 @@ struct video_jump_end : public Command {
 	}
 };
 
-
 /// Jumps the video to the start frame of current subtitle.
-struct video_jump_start : public Command {
+struct video_jump_start : public validator_video_loaded {
 	CMD_NAME("video/jump/start")
 	STR_MENU("Jump Video to Start")
 	STR_DISP("Jump Video to Start")
@@ -432,7 +429,6 @@ struct video_jump_start : public Command {
 	}
 };
 
-
 /// Opens a video file.
 struct video_open : public Command {
 	CMD_NAME("video/open")
@@ -452,7 +448,6 @@ struct video_open : public Command {
 	}
 };
 
-
 /// Opens a video clip with solid colour.
 struct video_open_dummy : public Command {
 	CMD_NAME("video/open/dummy")
@@ -481,7 +476,7 @@ struct video_opt_autoscroll : public Command {
 };
 
 /// Play video.
-struct video_play : public Command {
+struct video_play : public validator_video_loaded {
 	CMD_NAME("video/play")
 	STR_MENU("Play")
 	STR_DISP("Play")
@@ -493,7 +488,7 @@ struct video_play : public Command {
 };
 
 /// Play video for the active line.
-struct video_play_line : public Command {
+struct video_play_line : public validator_video_loaded {
 	CMD_NAME("video/play/line")
 	STR_MENU("Play line")
 	STR_DISP("Play line")
@@ -505,7 +500,7 @@ struct video_play_line : public Command {
 };
 
 /// Show a mask over the video.
-struct video_show_overscan : public Command {
+struct video_show_overscan : public validator_video_loaded {
 	CMD_NAME("video/show_overscan")
 	STR_MENU("Show Overscan Mask")
 	STR_DISP("Show Overscan Mask")
@@ -517,9 +512,8 @@ struct video_show_overscan : public Command {
 	}
 };
 
-
 /// Set zoom to 100%.
-class video_zoom_100: public Command {
+class video_zoom_100: public validator_video_attached {
 public:
 	CMD_NAME("video/zoom/100")
 	STR_MENU("&100%")
@@ -533,7 +527,7 @@ public:
 };
 
 /// Stop video playback
-class video_stop: public Command {
+class video_stop: public validator_video_loaded {
 public:
 	CMD_NAME("video/stop")
 	STR_MENU("Stop video")
@@ -546,7 +540,7 @@ public:
 };
 
 /// Set zoom to 200%.
-class video_zoom_200: public Command {
+class video_zoom_200: public validator_video_attached {
 public:
 	CMD_NAME("video/zoom/200")
 	STR_MENU("&200%")
@@ -559,9 +553,8 @@ public:
 	}
 };
 
-
 /// Set zoom to 50%.
-class video_zoom_50: public Command {
+class video_zoom_50: public validator_video_attached {
 public:
 	CMD_NAME("video/zoom/50")
 	STR_MENU("&50%")
@@ -574,9 +567,8 @@ public:
 	}
 };
 
-
 /// Zoom video in.
-struct video_zoom_in : public Command {
+struct video_zoom_in : public validator_video_attached {
 	CMD_NAME("video/zoom/in")
 	STR_MENU("Zoom In")
 	STR_DISP("Zoom In")
@@ -587,9 +579,8 @@ struct video_zoom_in : public Command {
 	}
 };
 
-
 /// Zoom video out.
-struct video_zoom_out : public Command {
+struct video_zoom_out : public validator_video_attached {
 	CMD_NAME("video/zoom/out")
 	STR_MENU("Zoom Out")
 	STR_DISP("Zoom Out")
diff --git a/aegisub/src/frame_main.cpp b/aegisub/src/frame_main.cpp
index 4ae3f817d..d1bafc9d9 100644
--- a/aegisub/src/frame_main.cpp
+++ b/aegisub/src/frame_main.cpp
@@ -764,15 +764,6 @@ void FrameMain::OnMenuOpen (wxMenuEvent &event) {
 
 	// View menu
 	else if (curMenu == menu::menu->GetMenu("main/view")) {
-		// Flags
-		bool aud = context->audioController->IsAudioOpen();
-		bool vid = context->videoController->IsLoaded() && !context->detachedVideo;
-
-		// Set states
-		MenuBar->Enable(cmd::id("app/display/audio_subs"),aud);
-		MenuBar->Enable(cmd::id("app/display/video_subs"),vid);
-		MenuBar->Enable(cmd::id("app/display/full"),aud && vid);
-
 		// Select option
 		if (!showVideo && !showAudio) MenuBar->Check(cmd::id("app/display/subs"),true);
 		else if (showVideo && !showAudio) MenuBar->Check(cmd::id("app/display/video_subs"),true);
@@ -783,37 +774,14 @@ void FrameMain::OnMenuOpen (wxMenuEvent &event) {
 		if (sub_grid == 1) MenuBar->Check(cmd::id("grid/tags/show"), true);
 		if (sub_grid == 2) MenuBar->Check(cmd::id("grid/tags/simplify"), true);
 		if (sub_grid == 3) MenuBar->Check(cmd::id("grid/tags/hide"), true);
-
-
 	}
-
 	// Video menu
 	else if (curMenu == menu::menu->GetMenu("main/video")) {
-		bool state = context->videoController->IsLoaded();
-		bool attached = state && !context->detachedVideo;
-
 		// Set states
-		MenuBar->Enable(cmd::id("video/jump"),state);
-		MenuBar->Enable(cmd::id("video/jump/start"),state);
-		MenuBar->Enable(cmd::id("video/jump/end"),state);
-		MenuBar->Enable(cmd::id("main/video/set zoom"), attached);
-		MenuBar->Enable(cmd::id("video/zoom/50"),attached);
-		MenuBar->Enable(cmd::id("video/zoom/100"),attached);
-		MenuBar->Enable(cmd::id("video/zoom/200"),attached);
-		MenuBar->Enable(cmd::id("video/close"),state);
-		MenuBar->Enable(cmd::id("main/video/override ar"),attached);
-		MenuBar->Enable(cmd::id("video/aspect/default"),attached);
-		MenuBar->Enable(cmd::id("video/aspect/full"),attached);
-		MenuBar->Enable(cmd::id("video/aspect/wide"),attached);
-		MenuBar->Enable(cmd::id("video/aspect/cinematic"),attached);
-		MenuBar->Enable(cmd::id("video/aspect/custom"),attached);
-		MenuBar->Enable(cmd::id("video/detach"),state);
 		MenuBar->Enable(cmd::id("timecode/save"),context->videoController->TimecodesLoaded());
 		MenuBar->Enable(cmd::id("timecode/close"),context->videoController->OverTimecodesLoaded());
 		MenuBar->Enable(cmd::id("keyframe/close"),context->videoController->OverKeyFramesLoaded());
 		MenuBar->Enable(cmd::id("keyframe/save"),context->videoController->KeyFramesLoaded());
-		MenuBar->Enable(cmd::id("video/details"),state);
-		MenuBar->Enable(cmd::id("video/show_overscan"),state);
 
 		// Set AR radio
 		int arType = context->videoController->GetAspectRatioType();
@@ -861,13 +829,7 @@ void FrameMain::OnMenuOpen (wxMenuEvent &event) {
 
 		// Entries
 		state = count > 0;
-		MenuBar->Enable(cmd::id("subtitle/insert/before"),state);
-		MenuBar->Enable(cmd::id("subtitle/insert/after"),state);
-		MenuBar->Enable(cmd::id("edit/line/split/by_karaoke"),state);
-		MenuBar->Enable(cmd::id("edit/line/delete"),state);
 		state2 = count > 0 && context->videoController->IsLoaded();
-		MenuBar->Enable(cmd::id("subtitle/insert/before/videotime"),state2);
-		MenuBar->Enable(cmd::id("subtitle/insert/after/videotime"),state2);
 		MenuBar->Enable(cmd::id("main/subtitle/insert lines"),state);
 		state = count > 0 && continuous;
 		MenuBar->Enable(cmd::id("edit/line/duplicate"),state);
diff --git a/aegisub/src/subs_grid.cpp b/aegisub/src/subs_grid.cpp
index f039b1876..9f3e536f0 100644
--- a/aegisub/src/subs_grid.cpp
+++ b/aegisub/src/subs_grid.cpp
@@ -188,11 +188,10 @@ void SubtitlesGrid::OnPopupMenu(bool alternate) {
 		// Duplicate selection
 		append_command(menu, "edit/line/duplicate", state);
 		append_command(menu, "edit/line/duplicate/shift", state);
-		append_command(menu, "edit/line/join/as_karaoke", state);
 
 		// Swaps selection
 		state = (sels == 2);
-		//append_command(menu, "MENU_SWAP", state);
+		append_command(menu, "edit/line/swap", state);
 
 		// Join selection
 		state = (sels >= 2 && continuous);