Reapply "Add cable management: drawing, cores, numbering, cross-references and cable list"

This reverts commit 2bb3343d2d.

sources/autoNum/ui/selectautonumw.h

@@ -27,6 +27,7 @@ class NumPartEditorW;
 class QAbstractButton;
 class FormulaAutonumberingW;
 class QComboBox;
+class QPushButton;
 class QToolButton;
 class QHBoxLayout;
 
@@ -54,11 +55,55 @@ class SelectAutonumW : public QWidget
 		void contextToFormula ();
 		QString formula();
 		QComboBox *contextComboBox() const;
+		/**
+			Show this editor as the only numbering rule there is: the
+			row which lets several named numberings be kept and chosen
+			between is hidden, so the rule being edited is the one and
+			only. Everything else -- the definition itself, the buttons
+			around it -- stays exactly as it is for the other kinds.
+		*/
+		void setSingleRuleMode(bool single);
+		bool isSingleRuleMode() const { return m_single_rule; }
+		/**
+			True while everything the editor holds is filled in well
+			enough to be a rule -- no variable left with nothing in it.
+			The Apply button says the same thing; this is so that a page
+			which saves on its own way knows it too, rather than writing
+			a rule nobody has finished filling in.
+		*/
+		bool isValid();
+		/**
+			True while the rule on show has been touched since it was
+			read or since it was last applied: a page which saves on
+			its own way (the cable rule does) writes it only when there
+			is something to write, so that confirming a window with
+			nothing changed in it leaves the project alone.
+		*/
+		bool isModified() const { return m_dirty; }
+		/**
+			Show the button which takes the rule itself away, which is
+			the only way to stop numbering cables automatically again:
+			the row the other numberings delete from is hidden here, so
+			a single rule would have no way out at all. The page behind
+			the editor says whether there is a rule to take away at the
+			moment -- without one the button has nothing to do and is
+			kept out of sight.
+			@param can_remove true when a rule is really there
+		*/
+		void setRuleRemovable(bool can_remove);
 		void setExplicitNaming();
 
 	signals:
 		void applyPressed();
 		void removeClicked();
+			/**
+				Sent whenever what the rule holds is edited -- a
+				field of a part changed, a part added, a part taken
+				away -- so that a window holding this editor can let
+				its own buttons say whether there is something to
+				write now.
+			*/
+		void contextEdited();
 			/// Only with setExplicitNaming()
 		void newClicked();
 		void renameClicked();
@@ -96,7 +141,19 @@ class SelectAutonumW : public QWidget
 		NumerotationContext m_context;
 		FormulaAutonumberingW *m_feaw;
 		FormulaAutonumberingW *m_fcaw;
-		int m_edited_type = -1; ///<0 == element : 1 == conductor : 2 == folio
+		int m_edited_type = -1; ///<0 == element : 1 == conductor : 2 == folio : 3 == cable
+			///< when true, the row of available numberings is hidden and
+			///< this editor holds the one rule there is (see setSingleRuleMode)
+		bool m_single_rule = false;
+			///< true from the moment the rule on show is touched until
+			///< it is read again or applied (see isModified)
+		bool m_dirty = false;
+			///< the button which takes the whole rule away, built for
+			///< the one kind of numbering which has no list to delete
+			///< it from (see setRuleRemovable)
+		QPushButton *m_rule_remove_pb = nullptr;
+			///< whether such a rule is there to be taken away
+		bool m_rule_removable = false;
 };
 
 #endif // SELECTAUTONUMW_H