Merge pull request #6057 from wonder-sk/layer-tree-filter-indicator

Layer tree view indicators API + filtered layer indicator

python/gui/gui_auto.sip

@@ -287,6 +287,7 @@
 %Include layertree/qgslayertreemapcanvasbridge.sip
 %Include layertree/qgslayertreeview.sip
 %Include layertree/qgslayertreeviewdefaultactions.sip
+%Include layertree/qgslayertreeviewindicator.sip
 %Include layout/qgslayoutcustomdrophandler.sip
 %Include layout/qgslayoutdesignerinterface.sip
 %Include layout/qgslayoutitemcombobox.sip

python/gui/layertree/qgslayertreeview.sip.in

@@ -109,6 +109,43 @@ Return list of selected nodes filtered to just layer nodes
     QList<QgsMapLayer *> selectedLayers() const;
 %Docstring
 Get list of selected layers
+%End
+
+    void addIndicator( QgsLayerTreeNode *node, QgsLayerTreeViewIndicator *indicator );
+%Docstring
+Adds an indicator to the given layer tree node. Indicators are icons shown next to layer/group names
+in the layer tree view. They can be used to show extra information with tree nodes and they allow
+user interaction.
+
+Does not take ownership of the indicator. One indicator object may be used for multiple layer tree nodes.
+
+.. seealso:: :py:func:`removeIndicator`
+
+.. seealso:: :py:func:`indicators`
+
+.. versionadded:: 3.2
+%End
+
+    void removeIndicator( QgsLayerTreeNode *node, QgsLayerTreeViewIndicator *indicator );
+%Docstring
+Removes a previously added indicator to a layer tree node. Does not delete the indicator.
+
+.. seealso:: :py:func:`addIndicator`
+
+.. seealso:: :py:func:`indicators`
+
+.. versionadded:: 3.2
+%End
+
+    QList<QgsLayerTreeViewIndicator *> indicators( QgsLayerTreeNode *node ) const;
+%Docstring
+Returns list of indicators associated with a particular layer tree node.
+
+.. seealso:: :py:func:`addIndicator`
+
+.. seealso:: :py:func:`removeIndicator`
+
+.. versionadded:: 3.2
 %End
 
   public slots:
@@ -153,7 +190,6 @@ Emitted when a current layer is changed
     virtual void dropEvent( QDropEvent *event );
 
 
-
   protected slots:
 
     void modelRowsInserted( const QModelIndex &index, int start, int end );
@@ -166,6 +202,7 @@ Emitted when a current layer is changed
     void onModelReset();
 
   protected:
+
 };
 
 

python/gui/layertree/qgslayertreeviewindicator.sip

@@ -0,0 +1,65 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/layertree/qgslayertreeviewindicator.h                        *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+class QgsLayerTreeViewIndicator : QObject
+{
+%Docstring
+Indicator that can be used in a layer tree view to display icons next to items of the layer tree.
+They add extra context to the item and interactivity (using clicked() signal).
+
+Indicators can be added/removed to individual layer tree items using :py:func:`QgsLayerTreeView.addIndicator()`
+and QgsLayerTreeView.removeIndicator() calls.
+
+.. versionadded:: 3.2
+%End
+
+%TypeHeaderCode
+#include "qgslayertreeviewindicator.h"
+%End
+  public:
+    explicit QgsLayerTreeViewIndicator( QObject *parent /TransferThis/ = 0 );
+%Docstring
+Constructs an indicator, optionally transferring ownership to a parent QObject
+%End
+
+    QIcon icon() const;
+%Docstring
+Indicator icon that will be displayed in the layer tree view
+%End
+    void setIcon( const QIcon &icon );
+%Docstring
+Sets indicator icon that will be displayed in the layer tree view
+%End
+
+    QString toolTip() const;
+%Docstring
+Returns tool tip text that will be shown when user hovers mouse over the indicator
+%End
+    void setToolTip( const QString &tip );
+%Docstring
+Sets tool tip text
+%End
+
+  signals:
+    void clicked( const QModelIndex &index );
+%Docstring
+Signal that is emitted when user clicks on the indicator
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/layertree/qgslayertreeviewindicator.h                        *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

src/app/CMakeLists.txt

@@ -52,6 +52,7 @@ SET(QGIS_APP_SRCS
   qgslabelengineconfigdialog.cpp
   qgslabelinggui.cpp
   qgslabelingwidget.cpp
+  qgslayertreeviewfilterindicator.cpp
   qgsloadstylefromdbdialog.cpp
   qgsmapcanvasdockwidget.cpp
   qgsmaplayerstyleguiutils.cpp
@@ -263,6 +264,7 @@ SET (QGIS_APP_MOC_HDRS
   qgslabelinggui.h
   qgslabelingwidget.h
   qgslabelpropertydialog.h
+  qgslayertreeviewfilterindicator.h
   qgsloadstylefromdbdialog.h
   qgsmapcanvasdockwidget.h
   qgsmaplayerstyleguiutils.h

src/app/qgisapp.cpp

@@ -201,6 +201,7 @@ Q_GUI_EXPORT extern int qt_defaultDpiX();
 #include "qgslayertreeutils.h"
 #include "qgslayertreeview.h"
 #include "qgslayertreeviewdefaultactions.h"
+#include "qgslayertreeviewfilterindicator.h"
 #include "qgslayout.h"
 #include "qgslayoutatlas.h"
 #include "qgslayoutcustomdrophandler.h"
@@ -3623,7 +3624,6 @@ void QgisApp::addUserInputWidget( QWidget *widget )
   mUserInputDockWidget->addUserInputWidget( widget );
 }
 
-
 void QgisApp::initLayerTreeView()
 {
   mLayerTreeView->setWhatsThis( tr( "Map legend that displays all the layers currently on the map canvas. Click on the checkbox to turn a layer on or off. Double-click on a layer in the legend to customize its appearance and set other properties." ) );
@@ -3646,6 +3646,7 @@ void QgisApp::initLayerTreeView()
 
   mLayerTreeView->setModel( model );
   mLayerTreeView->setMenuProvider( new QgsAppLayerTreeViewMenuProvider( mLayerTreeView, mMapCanvas ) );
+  new QgsLayerTreeViewFilterIndicatorProvider( mLayerTreeView );  // gets parented to the layer view
 
   setupLayerTreeViewFromSettings();
 

src/app/qgslayertreeviewfilterindicator.cpp

@@ -0,0 +1,207 @@
+/***************************************************************************
+  qgslayertreeviewfilterindicator.cpp
+  --------------------------------------
+  Date                 : January 2018
+  Copyright            : (C) 2018 by Martin Dobias
+  Email                : wonder dot sk at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgslayertreeviewfilterindicator.h"
+
+#include "qgslayertree.h"
+#include "qgslayertreemodel.h"
+#include "qgslayertreeview.h"
+#include "qgsquerybuilder.h"
+#include "qgsvectorlayer.h"
+
+
+QgsLayerTreeViewFilterIndicatorProvider::QgsLayerTreeViewFilterIndicatorProvider( QgsLayerTreeView *view )
+  : QObject( view )
+  , mLayerTreeView( view )
+{
+  mIcon = QgsApplication::getThemeIcon( QStringLiteral( "/mActionFilter2.svg" ) );
+
+  QgsLayerTree *tree = mLayerTreeView->layerTreeModel()->rootGroup();
+  onAddedChildren( tree, 0, tree->children().count() - 1 );
+
+  connect( tree, &QgsLayerTree::addedChildren, this, &QgsLayerTreeViewFilterIndicatorProvider::onAddedChildren );
+  connect( tree, &QgsLayerTree::willRemoveChildren, this, &QgsLayerTreeViewFilterIndicatorProvider::onWillRemoveChildren );
+}
+
+
+void QgsLayerTreeViewFilterIndicatorProvider::onAddedChildren( QgsLayerTreeNode *node, int indexFrom, int indexTo )
+{
+  // recursively connect to providers' dataChanged() signal
+
+  QList<QgsLayerTreeNode *> children = node->children();
+  for ( int i = indexFrom; i <= indexTo; ++i )
+  {
+    QgsLayerTreeNode *childNode = children[i];
+
+    if ( QgsLayerTree::isGroup( childNode ) )
+    {
+      onAddedChildren( childNode, 0, childNode->children().count() - 1 );
+    }
+    else if ( QgsLayerTree::isLayer( childNode ) )
+    {
+      QgsLayerTreeLayer *childLayerNode = QgsLayerTree::toLayer( childNode );
+      if ( QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( childLayerNode->layer() ) )
+      {
+        if ( vlayer->dataProvider() )
+        {
+          connect( vlayer->dataProvider(), &QgsDataProvider::dataChanged, this, &QgsLayerTreeViewFilterIndicatorProvider::onProviderDataChanged );
+
+          addOrRemoveIndicator( childLayerNode, vlayer->dataProvider() );
+        }
+      }
+      else if ( !childLayerNode->layer() )
+      {
+        // wait for layer to be loaded (e.g. when loading project, first the tree is loaded, afterwards the references to layers are resolved)
+        connect( childLayerNode, &QgsLayerTreeLayer::layerLoaded, this, &QgsLayerTreeViewFilterIndicatorProvider::onLayerLoaded );
+      }
+    }
+  }
+}
+
+
+void QgsLayerTreeViewFilterIndicatorProvider::onWillRemoveChildren( QgsLayerTreeNode *node, int indexFrom, int indexTo )
+{
+  // recursively disconnect from providers' dataChanged() signal
+
+  QList<QgsLayerTreeNode *> children = node->children();
+  for ( int i = indexFrom; i <= indexTo; ++i )
+  {
+    QgsLayerTreeNode *childNode = children[i];
+
+    if ( QgsLayerTree::isGroup( childNode ) )
+    {
+      onWillRemoveChildren( childNode, 0, childNode->children().count() - 1 );
+    }
+    else if ( QgsLayerTree::isLayer( childNode ) )
+    {
+      QgsLayerTreeLayer *childLayerNode = QgsLayerTree::toLayer( childNode );
+      if ( QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( childLayerNode->layer() ) )
+      {
+        if ( vlayer->dataProvider() )
+          disconnect( vlayer->dataProvider(), &QgsDataProvider::dataChanged, this, &QgsLayerTreeViewFilterIndicatorProvider::onProviderDataChanged );
+      }
+    }
+  }
+}
+
+
+void QgsLayerTreeViewFilterIndicatorProvider::onLayerLoaded()
+{
+  QgsLayerTreeLayer *nodeLayer = qobject_cast<QgsLayerTreeLayer *>( sender() );
+  if ( !nodeLayer )
+    return;
+
+  if ( QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( nodeLayer->layer() ) )
+  {
+    if ( vlayer->dataProvider() )
+    {
+      connect( vlayer->dataProvider(), &QgsDataProvider::dataChanged, this, &QgsLayerTreeViewFilterIndicatorProvider::onProviderDataChanged );
+
+      addOrRemoveIndicator( nodeLayer, vlayer->dataProvider() );
+    }
+  }
+}
+
+
+void QgsLayerTreeViewFilterIndicatorProvider::onProviderDataChanged()
+{
+  QgsVectorDataProvider *provider = qobject_cast<QgsVectorDataProvider *>( sender() );
+  if ( !provider )
+    return;
+
+  // walk the tree and find layer node that needs to be updated
+  const QList<QgsLayerTreeLayer *> layerNodes = mLayerTreeView->layerTreeModel()->rootGroup()->findLayers();
+  for ( QgsLayerTreeLayer *node : layerNodes )
+  {
+    if ( node->layer() && node->layer()->dataProvider() == provider )
+    {
+      addOrRemoveIndicator( node, provider );
+      break;
+    }
+  }
+}
+
+
+void QgsLayerTreeViewFilterIndicatorProvider::onIndicatorClicked( const QModelIndex &index )
+{
+  QgsLayerTreeNode *node = mLayerTreeView->layerTreeModel()->index2node( index );
+  if ( !QgsLayerTree::isLayer( node ) )
+    return;
+
+  QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( QgsLayerTree::toLayer( node )->layer() );
+  if ( !vlayer || !vlayer->dataProvider() )
+    return;
+
+  // launch the query builder
+  QgsQueryBuilder qb( vlayer );
+  qb.setSql( vlayer->dataProvider()->subsetString() );
+  if ( qb.exec() )
+    vlayer->dataProvider()->setSubsetString( qb.sql() );
+}
+
+QgsLayerTreeViewIndicator *QgsLayerTreeViewFilterIndicatorProvider::newIndicator( const QString &filter )
+{
+  QgsLayerTreeViewIndicator *indicator = new QgsLayerTreeViewIndicator( this );
+  indicator->setIcon( mIcon );
+  updateIndicator( indicator, filter );
+  connect( indicator, &QgsLayerTreeViewIndicator::clicked, this, &QgsLayerTreeViewFilterIndicatorProvider::onIndicatorClicked );
+  mIndicators.insert( indicator );
+  return indicator;
+}
+
+void QgsLayerTreeViewFilterIndicatorProvider::updateIndicator( QgsLayerTreeViewIndicator *indicator, const QString &filter )
+{
+  indicator->setToolTip( QString( "<b>%1:</b><br>%2" ).arg( tr( "Filter" ) ).arg( filter ) );
+}
+
+
+void QgsLayerTreeViewFilterIndicatorProvider::addOrRemoveIndicator( QgsLayerTreeNode *node, QgsVectorDataProvider *provider )
+{
+  QString filter = provider->subsetString();
+  if ( !filter.isEmpty() )
+  {
+    const QList<QgsLayerTreeViewIndicator *> nodeIndicators = mLayerTreeView->indicators( node );
+
+    // maybe the indicator exists already
+    foreach ( QgsLayerTreeViewIndicator *indicator, nodeIndicators )
+    {
+      if ( mIndicators.contains( indicator ) )
+      {
+        updateIndicator( indicator, filter );
+        return;
+      }
+    }
+
+    // it does not exist: need to create a new one
+    mLayerTreeView->addIndicator( node, newIndicator( filter ) );
+  }
+  else
+  {
+    const QList<QgsLayerTreeViewIndicator *> nodeIndicators = mLayerTreeView->indicators( node );
+
+    // there may be existing indicator we need to get rid of
+    foreach ( QgsLayerTreeViewIndicator *indicator, nodeIndicators )
+    {
+      if ( mIndicators.contains( indicator ) )
+      {
+        mLayerTreeView->removeIndicator( node, indicator );
+        indicator->deleteLater();
+        return;
+      }
+    }
+
+    // no indicator was there before, nothing to do
+  }
+}