[FEATURE][layouts] Add setting for label margin for map items

This setting allows per-map control of how close labels are permitted
to be placed to the map item's edges.

Sizes can be set using mm/inches/pixels/etc, and data defined
label margins are allowed.

Fixes #10314

python/core/auto_generated/layout/qgslayoutobject.sip.in

@@ -135,6 +135,7 @@ A base class for objects which belong to a layout.
       MapAtlasMargin,
       MapLayers,
       MapStylePreset,
+      MapLabelMargin,
       //composer picture
       PictureSource,
       PictureSvgBackgroundColor,

src/app/layout/qgslayoutmapwidget.cpp

@@ -75,6 +75,8 @@ QgsLayoutMapWidget::QgsLayoutMapWidget( QgsLayoutItemMap *item )
   connect( mOverviewCheckBox, &QgsCollapsibleGroupBoxBasic::toggled, this, &QgsLayoutMapWidget::mOverviewCheckBox_toggled );
   connect( mOverviewListWidget, &QListWidget::currentItemChanged, this, &QgsLayoutMapWidget::mOverviewListWidget_currentItemChanged );
   connect( mOverviewListWidget, &QListWidget::itemChanged, this, &QgsLayoutMapWidget::mOverviewListWidget_itemChanged );
+  connect( mLabelSettingsButton, &QPushButton::clicked, this, &QgsLayoutMapWidget::showLabelSettings );
+
   setPanelTitle( tr( "Map Properties" ) );
   mMapRotationSpinBox->setClearValue( 0 );
 
@@ -344,6 +346,12 @@ void QgsLayoutMapWidget::overviewSymbolChanged()
   mMapItem->update();
 }
 
+void QgsLayoutMapWidget::showLabelSettings()
+{
+  QgsLayoutMapLabelingWidget *w = new QgsLayoutMapLabelingWidget( mMapItem );
+  openPanel( w );
+}
+
 void QgsLayoutMapWidget::mAtlasCheckBox_toggled( bool checked )
 {
   if ( !mMapItem )
@@ -1635,3 +1643,53 @@ void QgsLayoutMapWidget::mOverviewCenterCheckbox_toggled( bool state )
   mMapItem->update();
   mMapItem->endCommand();
 }
+
+//
+// QgsLayoutMapLabelingWidget
+//
+
+QgsLayoutMapLabelingWidget::QgsLayoutMapLabelingWidget( QgsLayoutItemMap *map )
+  : QgsLayoutItemBaseWidget( nullptr, map )
+  , mMapItem( map )
+{
+  setupUi( this );
+  setPanelTitle( tr( "Label Settings" ) );
+
+  mLabelBoundarySpinBox->setClearValue( 0 );
+  mLabelBoundarySpinBox->setShowClearButton( true );
+
+  mLabelBoundaryUnitsCombo->linkToWidget( mLabelBoundarySpinBox );
+  mLabelBoundaryUnitsCombo->setConverter( &mMapItem->layout()->renderContext().measurementConverter() );
+
+  mLabelBoundarySpinBox->setValue( mMapItem->labelMargin().length() );
+  mLabelBoundaryUnitsCombo->setUnit( mMapItem->labelMargin().units() );
+
+  connect( mLabelBoundaryUnitsCombo, &QgsLayoutUnitsComboBox::changed, this, &QgsLayoutMapLabelingWidget::labelMarginUnitsChanged );
+  connect( mLabelBoundarySpinBox, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsLayoutMapLabelingWidget::labelMarginChanged );
+
+  registerDataDefinedButton( mLabelMarginDDBtn, QgsLayoutObject::MapLabelMargin );
+
+  updateDataDefinedButton( mLabelMarginDDBtn );
+}
+
+void QgsLayoutMapLabelingWidget::labelMarginChanged( double val )
+{
+  if ( !mMapItem )
+    return;
+
+  mMapItem->layout()->undoStack()->beginCommand( mMapItem, tr( "Change Label Margin" ), QgsLayoutItem::UndoMapLabelMargin );
+  mMapItem->setLabelMargin( QgsLayoutMeasurement( val, mLabelBoundaryUnitsCombo->unit() ) );
+  mMapItem->layout()->undoStack()->endCommand();
+  mMapItem->invalidateCache();
+}
+
+void QgsLayoutMapLabelingWidget::labelMarginUnitsChanged()
+{
+  if ( !mMapItem )
+    return;
+
+  mMapItem->layout()->undoStack()->beginCommand( mMapItem, tr( "Change Label Margin" ), QgsLayoutItem::UndoMapLabelMargin );
+  mMapItem->setLabelMargin( QgsLayoutMeasurement( mLabelBoundarySpinBox->value(), mLabelBoundaryUnitsCombo->unit() ) );
+  mMapItem->layout()->undoStack()->endCommand();
+  mMapItem->invalidateCache();
+}

src/app/layout/qgslayoutmapwidget.h

@@ -19,6 +19,7 @@
 #define QGSLAYOUTMAPWIDGET_H
 
 #include "ui_qgslayoutmapwidgetbase.h"
+#include "ui_qgslayoutmaplabelingwidgetbase.h"
 #include "qgslayoutitemwidget.h"
 #include "qgslayoutitemmapgrid.h"
 
@@ -116,6 +117,7 @@ class QgsLayoutMapWidget: public QgsLayoutItemBaseWidget, private Ui::QgsLayoutM
 
     void mapCrsChanged( const QgsCoordinateReferenceSystem &crs );
     void overviewSymbolChanged();
+    void showLabelSettings();
   private:
     QPointer< QgsLayoutItemMap > mMapItem;
     QgsLayoutItemPropertiesWidget *mItemPropertiesWidget = nullptr;
@@ -164,4 +166,24 @@ class QgsLayoutMapWidget: public QgsLayoutItemBaseWidget, private Ui::QgsLayoutM
 
 };
 
+
+/**
+ * \ingroup app
+ * Allows configuration of layout map labeling settings.
+ * */
+class QgsLayoutMapLabelingWidget: public QgsLayoutItemBaseWidget, private Ui::QgsLayoutMapLabelingWidgetBase
+{
+    Q_OBJECT
+
+  public:
+    explicit QgsLayoutMapLabelingWidget( QgsLayoutItemMap *map );
+
+  private slots:
+    void labelMarginChanged( double val );
+    void labelMarginUnitsChanged();
+
+  private:
+    QPointer< QgsLayoutItemMap > mMapItem;
+};
+
 #endif

src/core/layout/qgslayoutitemmap.cpp

@@ -742,7 +742,7 @@ bool QgsLayoutItemMap::readPropertiesFromElement( const QDomElement &itemElem, c
     mAtlasMargin = atlasElem.attribute( QStringLiteral( "margin" ), QStringLiteral( "0.1" ) ).toDouble();
   }
 
-  mLabelMargin = QgsLayoutMeasurement::decodeMeasurement( itemElem.attribute( QStringLiteral( "labelMargin" ), QStringLiteral( "0" ) ) );
+  setLabelMargin( QgsLayoutMeasurement::decodeMeasurement( itemElem.attribute( QStringLiteral( "labelMargin" ), QStringLiteral( "0" ) ) ) );
 
   updateBoundingRect();
 
@@ -1131,11 +1131,11 @@ QgsMapSettings QgsLayoutItemMap::mapSettings( const QgsRectangle &extent, QSizeF
   // override the default text render format inherited from the labeling engine settings using the layout's render context setting
   jobMapSettings.setTextRenderFormat( mLayout->renderContext().textRenderFormat() );
 
-  if ( mLabelMargin.length() > 0 )
+  if ( mEvaluatedLabelMargin.length() > 0 )
   {
     QPolygonF visiblePoly = jobMapSettings.visiblePolygon();
     visiblePoly.append( visiblePoly.at( 0 ) ); //close polygon
-    const double layoutLabelMargin = mLayout->convertToLayoutUnits( mLabelMargin );
+    const double layoutLabelMargin = mLayout->convertToLayoutUnits( mEvaluatedLabelMargin );
     const double layoutLabelMarginInMapUnits = layoutLabelMargin / rect().width() * jobMapSettings.extent().width();
     QgsGeometry mapBoundaryGeom = QgsGeometry::fromQPolygonF( visiblePoly );
     mapBoundaryGeom = mapBoundaryGeom.buffer( -layoutLabelMarginInMapUnits, 0 );
@@ -1335,6 +1335,10 @@ void QgsLayoutItemMap::refreshDataDefinedProperty( const QgsLayoutObject::DataDe
       emit extentChanged();
     }
   }
+  if ( property == QgsLayoutObject::MapLabelMargin || property == QgsLayoutObject::AllProperties )
+  {
+    refreshLabelMargin( false );
+  }
 
   //force redraw
   mCacheInvalidated = true;
@@ -1436,6 +1440,7 @@ QgsLayoutMeasurement QgsLayoutItemMap::labelMargin() const
 void QgsLayoutItemMap::setLabelMargin( const QgsLayoutMeasurement &margin )
 {
   mLabelMargin = margin;
+  refreshLabelMargin( false );
 }
 
 void QgsLayoutItemMap::updateToolTip()
@@ -1900,6 +1905,19 @@ void QgsLayoutItemMap::refreshMapExtents( const QgsExpressionContext *context )
   }
 }
 
+void QgsLayoutItemMap::refreshLabelMargin( bool updateItem )
+{
+  //data defined label margin set?
+  double labelMargin = mDataDefinedProperties.valueAsDouble( QgsLayoutObject::MapLabelMargin, createExpressionContext(), mLabelMargin.length() );
+  mEvaluatedLabelMargin.setLength( labelMargin );
+  mEvaluatedLabelMargin.setUnits( mLabelMargin.units() );
+
+  if ( updateItem )
+  {
+    update();
+  }
+}
+
 void QgsLayoutItemMap::updateAtlasFeature()
 {
   if ( !atlasDriven() || !mLayout->reportContext().layer() )

src/core/layout/qgslayoutitemmap.h

@@ -646,6 +646,7 @@ class CORE_EXPORT QgsLayoutItemMap : public QgsLayoutItem
     bool mPainterCancelWait = false;
 
     QgsLayoutMeasurement mLabelMargin{ 0 };
+    QgsLayoutMeasurement mEvaluatedLabelMargin{ 0 };
 
     void init();
 
@@ -694,6 +695,8 @@ class CORE_EXPORT QgsLayoutItemMap : public QgsLayoutItem
      */
     void refreshMapExtents( const QgsExpressionContext *context = nullptr );
 
+    void refreshLabelMargin( bool updateItem );
+
     void updateAtlasFeature();
 
     QgsRectangle computeAtlasRectangle();

src/core/layout/qgslayoutobject.cpp

@@ -63,6 +63,7 @@ void QgsLayoutObject::initPropertyDefinitions()
     { QgsLayoutObject::MapYMin, QgsPropertyDefinition( "dataDefinedMapYMin", QObject::tr( "Extent minimum Y" ), QgsPropertyDefinition::Double ) },
     { QgsLayoutObject::MapXMax, QgsPropertyDefinition( "dataDefinedMapXMax", QObject::tr( "Extent maximum X" ), QgsPropertyDefinition::Double ) },
     { QgsLayoutObject::MapYMax, QgsPropertyDefinition( "dataDefinedMapYMax", QObject::tr( "Extent maximum Y" ), QgsPropertyDefinition::Double ) },
+    { QgsLayoutObject::MapLabelMargin, QgsPropertyDefinition( "dataDefinedMapLabelMargin", QObject::tr( "Label margin" ), QgsPropertyDefinition::DoublePositive ) },
     { QgsLayoutObject::MapAtlasMargin, QgsPropertyDefinition( "dataDefinedMapAtlasMargin", QObject::tr( "Atlas margin" ), QgsPropertyDefinition::DoublePositive ) },
     { QgsLayoutObject::MapLayers, QgsPropertyDefinition( "dataDefinedMapLayers", QgsPropertyDefinition::DataTypeString, QObject::tr( "Map Layers" ), tr( "list of map layer names separated by | characters" ) ) },
     { QgsLayoutObject::MapStylePreset, QgsPropertyDefinition( "dataDefinedMapStylePreset", QgsPropertyDefinition::DataTypeString, QObject::tr( "Map theme" ), tr( "name of an existing map theme (case-sensitive)" ) ) },

src/core/layout/qgslayoutobject.h

@@ -163,6 +163,7 @@ class CORE_EXPORT QgsLayoutObject: public QObject, public QgsExpressionContextGe
       MapAtlasMargin, //!< Map atlas margin
       MapLayers, //!< Map layer set
       MapStylePreset, //!< Layer and style map theme
+      MapLabelMargin, //!< Map label margin
       //composer picture
       PictureSource, //!< Picture source url
       PictureSvgBackgroundColor, //!< SVG background color

src/ui/layout/qgslayoutmaplabelingwidgetbase.ui

@@ -0,0 +1,134 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>QgsLayoutMapLabelingWidgetBase</class>
+ <widget class="QWidget" name="QgsLayoutMapLabelingWidgetBase">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>326</width>
+    <height>424</height>
+   </rect>
+  </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
+    <horstretch>0</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
+  <property name="windowTitle">
+   <string>Map Options</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <property name="leftMargin">
+    <number>0</number>
+   </property>
+   <property name="topMargin">
+    <number>0</number>
+   </property>
+   <property name="rightMargin">
+    <number>0</number>
+   </property>
+   <property name="bottomMargin">
+    <number>0</number>
+   </property>
+   <item>
+    <widget class="QgsCollapsibleGroupBoxBasic" name="qgsCollapsibleGroupBoxBasic">
+     <property name="title">
+      <string>Label Settings</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout_6" columnstretch="0,0,0,0">
+      <item row="3" column="0" colspan="2">
+       <widget class="QLabel" name="label_10">
+        <property name="text">
+         <string>of map edges</string>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="0" colspan="2">
+       <widget class="QgsDoubleSpinBox" name="mLabelBoundarySpinBox">
+        <property name="prefix">
+         <string/>
+        </property>
+        <property name="minimum">
+         <double>0.000000000000000</double>
+        </property>
+        <property name="maximum">
+         <double>9999.000000000000000</double>
+        </property>
+        <property name="value">
+         <double>0.000000000000000</double>
+        </property>
+        <property name="showClearButton" stdset="0">
+         <bool>false</bool>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0" colspan="2">
+       <widget class="QLabel" name="label_8">
+        <property name="text">
+         <string>Avoid placing labels within</string>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="2">
+       <widget class="QgsLayoutUnitsComboBox" name="mLabelBoundaryUnitsCombo"/>
+      </item>
+      <item row="2" column="3">
+       <widget class="QgsPropertyOverrideButton" name="mLabelMarginDDBtn">
+        <property name="text">
+         <string>…</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <spacer name="verticalSpacer">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>40</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+  </layout>
+ </widget>
+ <layoutdefault spacing="6" margin="11"/>
+ <customwidgets>
+  <customwidget>
+   <class>QgsCollapsibleGroupBoxBasic</class>
+   <extends>QGroupBox</extends>
+   <header>qgscollapsiblegroupbox.h</header>
+   <container>1</container>
+  </customwidget>
+  <customwidget>
+   <class>QgsDoubleSpinBox</class>
+   <extends>QDoubleSpinBox</extends>
+   <header>qgsdoublespinbox.h</header>
+  </customwidget>
+  <customwidget>
+   <class>QgsPropertyOverrideButton</class>
+   <extends>QToolButton</extends>
+   <header>qgspropertyoverridebutton.h</header>
+  </customwidget>
+  <customwidget>
+   <class>QgsLayoutUnitsComboBox</class>
+   <extends>QComboBox</extends>
+   <header>qgslayoutunitscombobox.h</header>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>

src/ui/layout/qgslayoutmapwidgetbase.ui

@@ -63,9 +63,9 @@
       <property name="geometry">
        <rect>
         <x>0</x>
-        <y>-1556</y>
-        <width>627</width>
-        <height>2265</height>
+        <y>0</y>
+        <width>368</width>
+        <height>1373</height>
        </rect>
       </property>
       <property name="sizePolicy">
@@ -396,20 +396,27 @@
           <item row="4" column="0" colspan="2">
            <widget class="QPushButton" name="mSetToMapCanvasExtentButton">
             <property name="text">
-             <string>Set to map canvas extent</string>
+             <string>Set to Map Canvas Extent</string>
             </property>
            </widget>
           </item>
           <item row="5" column="0" colspan="2">
            <widget class="QPushButton" name="mViewExtentInCanvasButton">
             <property name="text">
-             <string>View extent in map canvas</string>
+             <string>View Extent in Map Canvas</string>
             </property>
            </widget>
           </item>
          </layout>
         </widget>
        </item>
+       <item>
+        <widget class="QPushButton" name="mLabelSettingsButton">
+         <property name="text">
+          <string>Label Settings…</string>
+         </property>
+        </widget>
+       </item>
        <item>
         <widget class="QgsCollapsibleGroupBoxBasic" name="mAtlasCheckBox">
          <property name="title">
@@ -600,7 +607,7 @@
             <item>
              <widget class="QPushButton" name="mGridPropertiesButton">
               <property name="text">
-               <string>Modify grid…</string>
+               <string>Modify Grid…</string>
               </property>
              </widget>
             </item>
@@ -793,9 +800,10 @@
    <container>1</container>
   </customwidget>
   <customwidget>
-   <class>QgsPropertyOverrideButton</class>
-   <extends>QToolButton</extends>
-   <header>qgspropertyoverridebutton.h</header>
+   <class>QgsCollapsibleGroupBoxBasic</class>
+   <extends>QGroupBox</extends>
+   <header>qgscollapsiblegroupbox.h</header>
+   <container>1</container>
   </customwidget>
   <customwidget>
    <class>QgsDoubleSpinBox</class>
@@ -807,17 +815,21 @@
    <extends>QSpinBox</extends>
    <header>qgsspinbox.h</header>
   </customwidget>
-  <customwidget>
-   <class>QgsCollapsibleGroupBoxBasic</class>
-   <extends>QGroupBox</extends>
-   <header location="global">qgscollapsiblegroupbox.h</header>
-   <container>1</container>
-  </customwidget>
   <customwidget>
    <class>QgsBlendModeComboBox</class>
    <extends>QComboBox</extends>
    <header>qgsblendmodecombobox.h</header>
   </customwidget>
+  <customwidget>
+   <class>QgsSymbolButton</class>
+   <extends>QToolButton</extends>
+   <header>qgssymbolbutton.h</header>
+  </customwidget>
+  <customwidget>
+   <class>QgsPropertyOverrideButton</class>
+   <extends>QToolButton</extends>
+   <header>qgspropertyoverridebutton.h</header>
+  </customwidget>
   <customwidget>
    <class>QgsProjectionSelectionWidget</class>
    <extends>QWidget</extends>
@@ -829,11 +841,6 @@
    <extends>QComboBox</extends>
    <header>qgslayoutitemcombobox.h</header>
   </customwidget>
-  <customwidget>
-   <class>QgsSymbolButton</class>
-   <extends>QToolButton</extends>
-   <header>qgssymbolbutton.h</header>
-  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>scrollArea</tabstop>
@@ -863,6 +870,7 @@
   <tabstop>mYMaxDDBtn</tabstop>
   <tabstop>mSetToMapCanvasExtentButton</tabstop>
   <tabstop>mViewExtentInCanvasButton</tabstop>
+  <tabstop>mLabelSettingsButton</tabstop>
   <tabstop>mAtlasCheckBox</tabstop>
   <tabstop>mAtlasMarginRadio</tabstop>
   <tabstop>mAtlasMarginSpinBox</tabstop>
@@ -920,6 +928,11 @@
   <include location="../../../images/images.qrc"/>
   <include location="../../../images/images.qrc"/>
   <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
  </resources>
  <connections/>
 </ui>

tests/src/python/test_qgslayoutmap.py

@@ -38,7 +38,9 @@ from qgis.core import (QgsLayoutItemMap,
                        QgsVectorLayerSimpleLabeling,
                        QgsLabelingEngineSettings,
                        QgsLayoutMeasurement,
-                       QgsUnitTypes)
+                       QgsUnitTypes,
+                       QgsLayoutObject,
+                       QgsProperty)
 
 from qgis.testing import start_app, unittest
 from utilities import unitTestDataPath
@@ -326,6 +328,17 @@ class TestQgsLayoutMap(unittest.TestCase, LayoutItemTestCase):
         self.report += checker.report()
         self.assertTrue(result, message)
 
+        # data defined
+        map.setMapRotation(0)
+        map.zoomToExtent(vl.extent())
+        map.dataDefinedProperties().setProperty(QgsLayoutObject.MapLabelMargin, QgsProperty.fromExpression('1+3'))
+        map.refresh()
+        checker = QgsLayoutChecker('composermap_dd_label_margin', layout)
+        checker.setControlPathPrefix("composer_map")
+        result, message = checker.testLayout()
+        self.report += checker.report()
+        self.assertTrue(result, message)
+
 
 if __name__ == '__main__':
     unittest.main()