dialogs can have a button respond to Escape

I'm planning to make it so the Enter key will never cancel a yes/no dialog. To do this, I'm adding an Escape button to dialogs. So cancel/accept keyboard shortcuts will be predictable and intuitive. Dialogs that require extra confirmation will have a 'really confirm' LED.

src/dialogxml/dialogs/dialog.cpp

@@ -158,7 +158,7 @@ void cDialog::loadFromFile(const DialogDefn& file){
 		
 		Iterator<Attribute> attr;
 		Iterator<Element> node;
-		string type, name, val, defbtn;
+		string type, name, val, defbtn, escbtn;
 		
 		xml.FirstChildElement()->GetValue(&type);
 		if(type != "dialog") throw xBadNode(type,xml.FirstChildElement()->Row(),xml.FirstChildElement()->Column(),fname);
@@ -181,8 +181,10 @@ void cDialog::loadFromFile(const DialogDefn& file){
 					throw xBadVal("text",name,val,attr->Row(),attr->Column(),fname);
 				}
 				defTextClr = clr;
-			} else if(name == "defbtn") {
+			}else if(name == "defbtn"){
 				defbtn = val;
+			}else if(name == "escbtn"){
+				escbtn = val;
 			}else if(name != "debug")
 				throw xBadAttr(type,name,attr->Row(),attr->Column(),fname);
 		}
@@ -337,6 +339,8 @@ void cDialog::loadFromFile(const DialogDefn& file){
 		
 		// Set the default button.
 		setDefaultButton(defbtn);
+		// Set the escape button.
+		setEscapeButton(escbtn);
 		
 		// Sort by tab order
 		// First, fill any gaps that might have been left, using ones that had no specific tab order
@@ -912,11 +916,12 @@ bool cDialog::addLabelFor(std::string key, std::string label, eLabelPos where, s
 void cDialog::process_keystroke(cKey keyHit){
 	ctrlIter iter = controls.begin();
 	bool enterKeyHit = keyHit.spec && keyHit.k == key_enter;
+	bool escapeKeyHit = keyHit.spec && keyHit.k == key_esc;
 	while(iter != controls.end()){
 		cControl* ctrl = iter->second;
 		if(ctrl->isVisible()){
 			if(ctrl->isClickable() &&
-				(ctrl->getAttachedKey() == keyHit || (ctrl->isDefault() && enterKeyHit))){
+				(ctrl->getAttachedKey() == keyHit || (ctrl->isDefault() && enterKeyHit) || (ctrl->isEscape() && escapeKeyHit))){
 
 				ctrl->handleKeyTriggered(*this);
 				return;
@@ -940,11 +945,6 @@ void cDialog::process_keystroke(cKey keyHit){
 		}
 		iter++;
 	}
-	// If you get an escape and it isn't processed, make it an enter.
-	if(keyHit.spec && keyHit.k == key_esc){
-		keyHit.k = key_enter;
-		process_keystroke(keyHit);
-	}
 }
 
 void cDialog::process_click(location where, eKeyMod mods, cFramerateLimiter& fps_limiter){
@@ -1157,21 +1157,38 @@ bool cDialog::hasControl(std::string id) const {
 	return false;
 }
 
-void cDialog::setDefaultButton(std::string defbtn) {
-	if(!defbtn.empty() && !hasControl(defbtn)){
+void cDialog::setSpecialButton(std::string& name_ref, std::string name, bool escape) {
+	if(!name.empty() && !hasControl(name)){
 		// this is likely because the dialogxml is malformed. maybe the linter already checks this,
 		// but the engine might as well also.
-		throw std::string { "Requested default button does not exist: " } + defbtn;
+		throw std::string { "Requested button does not exist: " } + name;
 	}
-	if(!defaultButton.empty()){
-		getControl(defaultButton).setDefault(false);
+	if(!name_ref.empty()){
+		if(escape){
+			getControl(name_ref).setEscape(false);
+		}else{
+			getControl(name_ref).setDefault(false);
+		}
+		name_ref = "";
 	}
-	if(!defbtn.empty()){
-		defaultButton = defbtn;
-		getControl(defaultButton).setDefault(true);
+	if(!name.empty()){
+		name_ref = name;
+		if(escape){
+			getControl(name).setEscape(true);
+		}else{
+			getControl(name).setDefault(true);
+		}
 	}
 }
 
+void cDialog::setDefaultButton(std::string defbtn) {
+	setSpecialButton(defaultButton, defbtn, false);
+}
+
+void cDialog::setEscapeButton(std::string escbtn) {
+	setSpecialButton(escapeButton, escbtn, true);
+}
+
 const char*const xBadVal::CONTENT = "$content$";
 
 cDialogIterator::cDialogIterator() : parent(nullptr) {}

src/dialogxml/dialogs/dialog.hpp

@@ -266,7 +266,9 @@ public:
 	inline void setAnimPictFPS(int fps) { if(fps == -1) fps = 2; anim_pict_fps = fps; }
 	inline void setDoAnimations(bool value) { doAnimations = value; }
 	void setDefaultButton(std::string defbtn);
+	void setEscapeButton(std::string escbtn);
 private:
+	void setSpecialButton(std::string& name_ref, std::string name, bool escape);
 	void draw();
 	void handle_events();
 	void handle_one_event(const sf::Event&, cFramerateLimiter& fps_limiter);
@@ -277,6 +279,7 @@ private:
 	boost::any result;
 	std::string fname;
 	std::string defaultButton;
+	std::string escapeButton;
 	sf::Clock animTimer, paintTimer;
 	friend class cControl;
 	friend class cContainer;

src/dialogxml/widgets/control.hpp

@@ -172,6 +172,8 @@ public:
 	std::string getAttachedKeyDescription() const;
 	inline void setDefault(bool value) { isDefaultControl = value; }
 	inline bool isDefault() { return isDefaultControl; }
+	inline void setEscape(bool value) { isEscapeControl = value; }
+	inline bool isEscape() { return isEscapeControl; }
 	/// Attach an event handler to this control.
 	/// @tparam t The type of event to attach.
 	/// @param handler The event handler function or functor. Its signature depends on the event type.
@@ -477,6 +479,8 @@ protected:
 	cKey key;
 	/// Whether the control is the default control of its dialog.
 	bool isDefaultControl = false;
+	/// Whether the control is the cancel control of its dialog.
+	bool isEscapeControl = false;
 
 	/// Draw a frame around the control.
 	/// @param amt How much to offset the frame from the control's bounding rect.