Add a wires-per-terminal limit, with an application master switch

Discussion #1158: a real terminal takes one or two wires (four with
double ferrules), a folio report is a virtual point that carries one, but
QElectroTech lets any number of wires be connected anywhere.

Project properties > General gets a "Conducteurs par borne" group:
- the most wires a terminal may take (0, the default, is no limit);
- "one wire per folio report".
When set, a new wire that would go past the limit is refused: the
terminal shows red while dragging, as for any refused link, and a tooltip
says why on release. Auto-connect on placing, moving or multi-pasting a
symbol skips full terminals, and qet.addConductor() refuses with its own
message. Wires already drawn, opening, pasting and undo are never
refused.

Settings > General gets a master switch, on by default, that turns every
rule of this feature off in every project; the project group is greyed
with a note while it is off.

The rules live in wiringrules.cpp. The project setting is saved as
<wiring_rules .../> only when a rule is on, so a project that never used
it saves exactly as before; an older version drops it, which means "off".

tst_wiringrules covers the rules, the save round trip and, through the
real binary, that a wire past the limit is refused unless the master
switch is off (checked to fail with the limit check removed).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015FPuYPS4T7QuEwjNu22rXD

sources/ui/configpage/generalconfigurationpage.cpp

@@ -27,6 +27,7 @@
 #include "../../utils/qetutils.h"
 #include "../../qetmessagebox.h"
 #include "../../textgrid.h"
+#include "../../wiringrules.h"
 #include "../../editor/terminalnamecheck.h"
 #include "../../ElementsCollection/qetlabelsfile.h"
 #include "../prefixconfigurationdialog.h"
@@ -113,6 +114,7 @@ GeneralConfigurationPage::GeneralConfigurationPage(QWidget *parent) :
 		ui->m_use_windows_mode_rb->setChecked(true);
 	ui->m_zoom_out_beyond_folio->setChecked(settings.value("diagrameditor/zoom-out-beyond-of-folio", false).toBool());
 	ui->m_conductor_properties_panel->setChecked(settings.value("diagrameditor/conductor_properties_panel", false).toBool());
+	ui->m_wiring_rules_cb->setChecked(WiringRules::masterEnabled());
 	ui->m_use_gesture_trackpad->setChecked(settings.value("diagramview/gestures", false).toBool());
 	ui->m_save_label_paste->setChecked(settings.value("diagramcommands/erase-label-on-copy", true).toBool());
 	ui->m_enable_scripting->setChecked(QetSettings::scriptingEnabled());
@@ -334,6 +336,7 @@ void GeneralConfigurationPage::applyConf()
 	settings.setValue("diagrameditor/highlight-integrated-elements", ui->m_highlight_integrated_elements->isChecked());
 	settings.setValue("diagrameditor/zoom-out-beyond-of-folio", ui->m_zoom_out_beyond_folio->isChecked());
 	settings.setValue("diagrameditor/conductor_properties_panel", ui->m_conductor_properties_panel->isChecked());
+	WiringRules::setMasterEnabled(ui->m_wiring_rules_cb->isChecked());
 	settings.setValue("diagrameditor/autosave-interval", ui->m_autosave_sb->value());
 
 	settings.setValue("diagrameditor/grid_display_startup", ui->grid_startup_cb->isChecked());

sources/ui/configpage/generalconfigurationpage.ui

@@ -70,6 +70,19 @@
          </property>
         </widget>
        </item>
+       <item>
+        <widget class="QCheckBox" name="m_wiring_rules_cb">
+         <property name="toolTip">
+          <string>Décoché, aucune règle de conducteurs par borne n'est appliquée, quels que soient les réglages des projets.</string>
+         </property>
+         <property name="text">
+          <string>Appliquer les règles de conducteurs par borne des projets</string>
+         </property>
+         <property name="checked">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
        <item>
         <widget class="Line" name="line_2">
          <property name="orientation">
@@ -1297,6 +1310,7 @@ Vous pouvez spécifier ici la valeur par défaut de ce champ pour les éléments
   <tabstop>m_use_gesture_trackpad</tabstop>
   <tabstop>m_zoom_out_beyond_folio</tabstop>
   <tabstop>m_conductor_properties_panel</tabstop>
+  <tabstop>m_wiring_rules_cb</tabstop>
   <tabstop>m_use_windows_mode_rb</tabstop>
   <tabstop>m_use_tab_mode_rb</tabstop>
   <tabstop>m_save_label_paste</tabstop>

sources/ui/configpage/projectconfigpages.cpp

@@ -26,6 +26,7 @@
 #include "../qet.h"
 #include "../qeticons.h"
 #include "../qetproject.h"
+#include "../wiringrules.h"
 #include "../borderpropertieswidget.h"
 #include "../conductorpropertieswidget.h"
 #include "../diagramcontextwidget.h"
@@ -176,6 +177,14 @@ void ProjectMainConfigPage::applyProjectConf()
 		modified_project = true;
 	}
 
+	WiringRules::Settings wiring_rules = m_project -> wiringRules();
+	wiring_rules.max_wires = max_wires_sb_ -> value();
+	wiring_rules.one_wire_per_report = one_wire_per_report_cb_ -> isChecked();
+	if (m_project -> wiringRules() != wiring_rules) {
+		m_project -> setWiringRules(wiring_rules);
+		modified_project = true;
+	}
+
 	if (modified_project) {
 		m_project -> setModified(true);
 	}
@@ -225,6 +234,25 @@ void ProjectMainConfigPage::initWidgets()
 	wire_hops_cb_ -> setToolTip(tr("Dessine un petit arc là où deux conducteurs se croisent sans être reliés. "
 								   "Seul le dessin change : aucun élément n'est ajouté et aucun conducteur n'est coupé.",
 								   "tooltip"));
+
+		//How many wires a terminal may take (discussion #1158)
+	wiring_rules_gb_ = new QGroupBox(tr("Conducteurs par borne", "group box title"));
+	max_wires_label_ = new QLabel(tr("Nombre maximal de conducteurs par borne :", "label when configuring"));
+	max_wires_sb_ = new QSpinBox();
+	max_wires_sb_ -> setRange(0, 99);
+	max_wires_sb_ -> setSpecialValueText(tr("Sans limite", "wires per terminal"));
+	max_wires_sb_ -> setToolTip(tr("Un nouveau conducteur qui dépasserait ce nombre sur une borne est refusé. "
+								   "Les conducteurs déjà dessinés ne sont pas modifiés. "
+								   "4 correspond à deux embouts doubles, un de chaque côté de la vis.",
+								   "tooltip"));
+	one_wire_per_report_cb_ = new QCheckBox(tr("Un seul conducteur par renvoi de folio", "checkbox label"));
+	one_wire_per_report_cb_ -> setToolTip(tr("Un renvoi de folio est un point virtuel : il ne reçoit qu'un conducteur, "
+											 "celui qui continue sur l'autre folio.",
+											 "tooltip"));
+	wiring_rules_off_label_ = new QLabel(tr("Ces règles sont désactivées pour tous les projets "
+											"(Configurer QElectroTech > Général).",
+											"informative label"));
+	wiring_rules_off_label_ -> setWordWrap(true);
 }
 
 /**
@@ -257,6 +285,17 @@ void ProjectMainConfigPage::initLayout()
 	wire_hops_layout0 -> addWidget(wire_hops_cb_);
 	wire_hops_layout0 -> addStretch();
 	main_layout0 -> addLayout(wire_hops_layout0);
+	main_layout0 -> addSpacing(10);
+
+	QVBoxLayout *wiring_rules_layout = new QVBoxLayout(wiring_rules_gb_);
+	QHBoxLayout *max_wires_layout = new QHBoxLayout();
+	max_wires_layout -> addWidget(max_wires_label_);
+	max_wires_layout -> addWidget(max_wires_sb_);
+	max_wires_layout -> addStretch();
+	wiring_rules_layout -> addLayout(max_wires_layout);
+	wiring_rules_layout -> addWidget(one_wire_per_report_cb_);
+	wiring_rules_layout -> addWidget(wiring_rules_off_label_);
+	main_layout0 -> addWidget(wiring_rules_gb_);
 
 	setLayout(main_layout0);
 	this -> setMinimumWidth(680);
@@ -280,6 +319,17 @@ void ProjectMainConfigPage::readValuesFromProject()
 
 	const int wire_hops_index = wire_hops_cb_ -> findData(WireHops::toString(m_project -> wireHops()));
 	wire_hops_cb_ -> setCurrentIndex(qMax(0, wire_hops_index));
+
+	const WiringRules::Settings wiring_rules = m_project -> wiringRules();
+	max_wires_sb_ -> setValue(wiring_rules.max_wires);
+	one_wire_per_report_cb_ -> setChecked(wiring_rules.one_wire_per_report);
+		//The master switch wins over every project: say so rather than
+		//let the user set a rule that does nothing.
+	const bool master = WiringRules::masterEnabled();
+	wiring_rules_off_label_ -> setVisible(!master);
+	max_wires_label_ -> setEnabled(master);
+	max_wires_sb_ -> setEnabled(master);
+	one_wire_per_report_cb_ -> setEnabled(master);
 }
 
 /**
@@ -307,6 +357,7 @@ void ProjectMainConfigPage::adjustReadOnly()
 	usage_enabled_cb_ -> setDisabled(is_read_only);
 	usage_reset_pb_ -> setDisabled(is_read_only);
 	wire_hops_cb_ -> setDisabled(is_read_only);
+	wiring_rules_gb_ -> setDisabled(is_read_only);
 }
 
 //######################################################################################//

sources/ui/configpage/projectconfigpages.h

@@ -24,6 +24,8 @@ class QComboBox;
 class QLineEdit;
 class QCheckBox;
 class QPushButton;
+class QSpinBox;
+class QGroupBox;
 class QETProject;
 class BorderPropertiesWidget;
 class ConductorPropertiesWidget;
@@ -128,6 +130,11 @@ class ProjectMainConfigPage : public ProjectConfigPage {
 	QPushButton *usage_reset_pb_;
 	QLabel *wire_hops_label_;
 	QComboBox *wire_hops_cb_;
+	QGroupBox *wiring_rules_gb_;
+	QLabel *max_wires_label_;
+	QSpinBox *max_wires_sb_;
+	QCheckBox *one_wire_per_report_cb_;
+	QLabel *wiring_rules_off_label_;
 };
 
 class ProjectAutoNumConfigPage : public ProjectConfigPage {