Factor out the placeholder text behavior from SubsEditBox and make it work better

Handle switching from placeholder/normal mode when the value is changed
externally (such as from the active line changing) in addition to on
focus/blur, and improve behavior when the user sets the text to the
placeholder text.

Originally committed to SVN as r6321.

aegisub/build/aegisub_vs2008/aegisub_vs2008.vcproj

@@ -633,6 +633,10 @@
 				RelativePath="..\..\src\help_button.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\placeholder_ctrl.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\scintilla_text_ctrl.cpp"
 				>

aegisub/src/placeholder_ctrl.h

@@ -0,0 +1,104 @@
+// Copyright (c) 2012, Thomas Goyne <plorkyeran@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+// Aegisub Project http://www.aegisub.org/
+//
+// $Id$
+
+/// @file placeholder_ctrl.h
+/// @ingroup custom_control
+///
+
+#ifndef AGI_PRE
+#include <wx/settings.h>
+#endif
+
+/// @class Placeholder
+/// @brief A wrapper around a control to add placeholder text
+///
+/// This control wraps a base control to add default greyed-out placeholder
+/// text describing the control when the value would otherwise be empty, which
+/// is removed when the control is focused to begin typing in it, and restored
+/// when the control loses focus and the value is empty
+template<class BaseCtrl>
+class Placeholder : public BaseCtrl {
+	wxString placeholder; ///< Placeholder string
+	bool is_placeholder;  ///< Should the value be cleared on focus?
+
+	/// Wrapper around Create to make it possible to override it for specific
+	/// base classes
+	inline void Create(wxWindow *parent, wxSize const& size, long style) {
+		BaseCtrl::Create(parent, -1, placeholder, wxDefaultPosition, size, style);
+	}
+
+	/// Focus gained event handler
+	void OnSetFocus(wxFocusEvent& evt) {
+		evt.Skip();
+
+		if (is_placeholder) {
+			BaseCtrl::ChangeValue("");
+			BaseCtrl::SetForegroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
+		}
+	}
+
+	/// Focus lost event handler
+	void OnKillFocus(wxFocusEvent& evt) {
+		evt.Skip();
+		ChangeValue(BaseCtrl::GetValue());
+	}
+
+public:
+	/// Constructor
+	/// @param parent Parent window
+	/// @param placeholder Placeholder string
+	/// @param size Control size
+	/// @param style Style flags to pass to the base control
+	/// @param tooltip Tooltip string
+	Placeholder(wxWindow *parent, wxString const& placeholder, wxSize const& size, long style, wxString const& tooltip)
+	: placeholder(placeholder)
+	, is_placeholder(true)
+	{
+		Create(parent, size, style);
+		BaseCtrl::SetToolTip(tooltip);
+		BaseCtrl::SetForegroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_GRAYTEXT));
+
+		BaseCtrl::Bind(wxEVT_SET_FOCUS, &Placeholder::OnSetFocus, this);
+		BaseCtrl::Bind(wxEVT_KILL_FOCUS, &Placeholder::OnKillFocus, this);
+	}
+
+	/// @brief Change the value of the control without triggering events
+	/// @param new_value New value of the control
+	///
+	/// If new_value is empty, the control will switch to placeholder mode
+	void ChangeValue(wxString new_value) {
+		if (new_value.empty()) {
+			is_placeholder = true;
+			new_value = placeholder;
+			BaseCtrl::SetForegroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_GRAYTEXT));
+		}
+		else {
+			is_placeholder = false;
+			BaseCtrl::SetForegroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
+		}
+
+		// This check should be pointless, but wxGTK is awesome and generates
+		// change events in wxComboBox::ChangeValue
+		if (new_value != BaseCtrl::GetValue())
+			BaseCtrl::ChangeValue(new_value);
+	}
+};
+
+template<> inline void Placeholder<wxComboBox>::Create(wxWindow *parent, wxSize const& size, long style) {
+	wxComboBox::Create(parent, -1, "", wxDefaultPosition, size, 0, 0, style);
+}

aegisub/src/subs_edit_box.cpp

@@ -63,6 +63,7 @@
 #include "include/aegisub/hotkey.h"
 #include "libresrc/libresrc.h"
 #include "main.h"
+#include "placeholder_ctrl.h"
 #include "subs_edit_ctrl.h"
 #include "subs_grid.h"
 #include "timeedit_ctrl.h"
@@ -113,34 +114,6 @@ static T get_value(AssDialogue const& line, int blockn, T initial, wxString tag,
 	return initial;
 }
 
-template<class Control>
-struct FocusHandler : std::unary_function<wxFocusEvent &, void> {
-	wxString value;
-	wxString alt;
-	wxColor color;
-	Control *control;
-	void operator()(wxFocusEvent &event) const {
-		event.Skip();
-
-		if (control->GetValue() == alt) {
-			control->Freeze();
-			control->ChangeValue(value);
-			control->SetForegroundColour(color);
-			control->Thaw();
-		}
-	}
-};
-
-template<class Event, class T>
-void bind_focus_handler(T *control, Event event, wxString value, wxString alt, wxColor color) {
-	FocusHandler<T> handler;
-	handler.value = value;
-	handler.alt = alt;
-	handler.color = color;
-	handler.control = control;
-	control->Bind(event, handler);
-}
-
 /// Get the block index in the text of the position
 int block_at_pos(wxString const& text, int pos) {
 	int n = 0;
@@ -182,10 +155,14 @@ SubsEditBox::SubsEditBox(wxWindow *parent, agi::Context *context)
 	TopSizer->Add(CommentBox, 0, wxRIGHT | wxALIGN_CENTER, 5);
 
 	StyleBox = MakeComboBox("Default", wxCB_READONLY, &SubsEditBox::OnStyleChange, _("Style for this line."));
-	ActorBox = MakeComboBox("Actor", wxCB_DROPDOWN, &SubsEditBox::OnActorChange, _("Actor name for this speech. This is only for reference, and is mainly useless."));
 
-	Effect = new wxTextCtrl(this,-1,"",wxDefaultPosition,wxSize(80,-1),wxTE_PROCESS_ENTER);
+	ActorBox = new Placeholder<wxComboBox>(this, "Actor", wxSize(110, -1), wxCB_DROPDOWN | wxTE_PROCESS_ENTER, _("Actor name for this speech. This is only for reference, and is mainly useless."));
-	Effect->SetToolTip(_("Effect for this line. This can be used to store extra information for karaoke scripts, or for the effects supported by the renderer."));
+	Bind(wxEVT_COMMAND_TEXT_UPDATED, &SubsEditBox::OnActorChange, this, ActorBox->GetId());
+	Bind(wxEVT_COMMAND_COMBOBOX_SELECTED, &SubsEditBox::OnActorChange, this, ActorBox->GetId());
+	TopSizer->Add(ActorBox, wxSizerFlags(2).Center().Border(wxRIGHT));
+
+	Effect = new Placeholder<wxTextCtrl>(this, "Effect", wxSize(80,-1), wxTE_PROCESS_ENTER, _("Effect for this line. This can be used to store extra information for karaoke scripts, or for the effects supported by the renderer."));
+	Bind(wxEVT_COMMAND_TEXT_UPDATED, &SubsEditBox::OnEffectChange, this, Effect->GetId());
 	TopSizer->Add(Effect, 3, wxALIGN_CENTER, 5);
 
 	// Middle controls
@@ -243,24 +220,11 @@ SubsEditBox::SubsEditBox(wxWindow *parent, agi::Context *context)
 
 	SetSizerAndFit(MainSizer);
 
-	wxColour text = wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT);
-	wxColour grey = wxSystemSettings::GetColour(wxSYS_COLOUR_GRAYTEXT);
-
-	// Setup placeholders for effect and actor boxes
-	bind_focus_handler(Effect, wxEVT_SET_FOCUS, "", "Effect", text);
-	bind_focus_handler(Effect, wxEVT_KILL_FOCUS, "Effect", "", grey);
-	Effect->SetForegroundColour(grey);
-
-	bind_focus_handler(ActorBox, wxEVT_SET_FOCUS, "", "Actor", text);
-	bind_focus_handler(ActorBox, wxEVT_KILL_FOCUS, "Actor", "", grey);
-	ActorBox->SetForegroundColour(grey);
-
 	TextEdit->Bind(wxEVT_STC_MODIFIED, &SubsEditBox::OnChange, this);
 	TextEdit->SetModEventMask(wxSTC_MOD_INSERTTEXT | wxSTC_MOD_DELETETEXT);
 
 	Bind(wxEVT_COMMAND_TEXT_UPDATED, &SubsEditBox::OnLayerEnter, this, Layer->GetId());
 	Bind(wxEVT_COMMAND_SPINCTRL_UPDATED, &SubsEditBox::OnLayerChange, this, Layer->GetId());
-	Bind(wxEVT_COMMAND_TEXT_UPDATED, &SubsEditBox::OnEffectChange, this, Effect->GetId());
 	Bind(wxEVT_COMMAND_CHECKBOX_CLICKED, &SubsEditBox::OnCommentChange, this, CommentBox->GetId());
 
 	Bind(wxEVT_SIZE, &SubsEditBox::OnSize, this);
@@ -361,12 +325,12 @@ void SubsEditBox::OnCommit(int type) {
 		change_value(MarginL, line->GetMarginString(0,false));
 		change_value(MarginR, line->GetMarginString(1,false));
 		change_value(MarginV, line->GetMarginString(2,false));
-		Effect->ChangeValue(line->Effect.empty() ? "Effect" : line->Effect);
+		Effect->ChangeValue(line->Effect);
 		CommentBox->SetValue(line->Comment);
 		StyleBox->Select(StyleBox->FindString(line->Style));
 
 		PopulateActorList();
-		ActorBox->ChangeValue(line->Actor.empty() ? "Actor" : line->Actor);
+		ActorBox->ChangeValue(line->Actor);
 		ActorBox->SetStringSelection(line->Actor);
 	}
 }

aegisub/src/subs_edit_box.h

@@ -45,6 +45,7 @@
 
 #include "selection_controller.h"
 
+namespace agi { namespace vfr { class Framerate; } }
 namespace agi { struct Context; }
 struct AssColor;
 class AssDialogue;
@@ -61,7 +62,7 @@ class wxStyledTextCtrl;
 class wxStyledTextEvent;
 class wxTextCtrl;
 
-namespace agi { namespace vfr { class Framerate; } }
+template<class Base> class Placeholder;
 
 /// DOCME
 /// @class SubsEditBox
@@ -92,7 +93,7 @@ class SubsEditBox : public wxPanel, protected SelectionListener<AssDialogue> {
 	// Box controls
 	wxCheckBox *CommentBox;
 	wxComboBox *StyleBox;
-	wxComboBox *ActorBox;
+	Placeholder<wxComboBox> *ActorBox;
 	TimeEdit *StartTime;
 	TimeEdit *EndTime;
 	TimeEdit *Duration;
@@ -100,7 +101,7 @@ class SubsEditBox : public wxPanel, protected SelectionListener<AssDialogue> {
 	wxTextCtrl *MarginL;
 	wxTextCtrl *MarginR;
 	wxTextCtrl *MarginV;
-	wxTextCtrl *Effect;
+	Placeholder<wxTextCtrl> *Effect;
 	wxRadioButton *ByTime;
 	wxRadioButton *ByFrame;
 
@@ -159,6 +160,8 @@ class SubsEditBox : public wxPanel, protected SelectionListener<AssDialogue> {
 	void OnColorButton(AssColor (AssStyle::*field), const char *tag, const char *alt);
 	void OnFontButton();
 
+	void SetPlaceholderCtrl(wxControl *ctrl, wxString const& value);
+
 	/// @brief Set the value of a tag for the currently selected text
 	/// @param tag   Tag to set
 	/// @param value New value of tag