[FEATURE] Add scalebar sizing mode to fit a desired scalebar width (fix #8995)

manisandro · nyalldawson · commit 45bdae461dc6 · 2015-05-07T22:25:15.000+10:00
diff --git a/python/core/composer/qgscomposerscalebar.sip b/python/core/composer/qgscomposerscalebar.sip
@@ -25,6 +25,14 @@ class QgsComposerScaleBar: QgsComposerItem
       NauticalMiles
     };
 
+    /** Modes for setting size for scale bar segments
+    */
+    enum SegmentSizeMode
+    {
+      SegmentSizeFixed, /*!< Scale bar segment size is fixed to a map unit*/
+      SegmentSizeFitWidth /*!< Scale bar segment size is calculated to fit a size range*/
+    };
+
     QgsComposerScaleBar( QgsComposition* composition /TransferThis/ );
     ~QgsComposerScaleBar();
 
@@ -44,6 +52,65 @@ class QgsComposerScaleBar: QgsComposerItem
     double numUnitsPerSegment() const;
     void setNumUnitsPerSegment( double units );
 
+    /** Returns the size mode for scale bar segments.
+     * @see setSegmentSizeMode
+     * @see minBarWidth
+     * @see maxBarWidth
+     * @note added in QGIS 2.9
+     */
+    SegmentSizeMode segmentSizeMode() const;
+
+    /** Sets the size mode for scale bar segments.
+     * @param mode size mode
+     * @see segmentSizeMode
+     * @see setMinBarWidth
+     * @see setMaxBarWidth
+     * @note added in QGIS 2.9
+     */
+    void setSegmentSizeMode( SegmentSizeMode mode );
+
+    /** Returns the minimum size (in millimeters) for scale bar segments. This
+     * property is only effective if the @link segmentSizeMode @endlink is set
+     * to @link SegmentSizeFitWidth @endlink.
+     * @see segmentSizeMode
+     * @see setMinBarWidth
+     * @see maxBarWidth
+     * @note added in QGIS 2.9
+     */
+    double minBarWidth() const;
+
+    /** Sets the minimum size (in millimeters) for scale bar segments. This
+     * property is only effective if the @link segmentSizeMode @endlink is set
+     * to @link SegmentSizeFitWidth @endlink.
+     * @param minWidth minimum width in millimeters
+     * @see minBarWidth
+     * @see setMaxBarWidth
+     * @see setSegmentSizeMode
+     * @note added in QGIS 2.9
+     */
+    void setMinBarWidth( double minWidth );
+
+    /** Returns the maximum size (in millimeters) for scale bar segments. This
+     * property is only effective if the @link segmentSizeMode @endlink is set
+     * to @link SegmentSizeFitWidth @endlink.
+     * @see segmentSizeMode
+     * @see setMaxBarWidth
+     * @see minBarWidth
+     * @note added in QGIS 2.9
+     */
+    double maxBarWidth() const;
+
+    /** Sets the maximum size (in millimeters) for scale bar segments. This
+     * property is only effective if the @link segmentSizeMode @endlink is set
+     * to @link SegmentSizeFitWidth @endlink.
+     * @param minWidth maximum width in millimeters
+     * @see minBarWidth
+     * @see setMaxBarWidth
+     * @see setSegmentSizeMode
+     * @note added in QGIS 2.9
+     */
+    void setMaxBarWidth( double maxWidth );
+
     double numMapUnitsPerScaleBarUnit() const;
     void setNumMapUnitsPerScaleBarUnit( double d );
 
diff --git a/src/app/composer/qgscomposerscalebarwidget.cpp b/src/app/composer/qgscomposerscalebarwidget.cpp
@@ -32,6 +32,10 @@ QgsComposerScaleBarWidget::QgsComposerScaleBarWidget( QgsComposerScaleBar* scale
   QgsComposerItemWidget* itemPropertiesWidget = new QgsComposerItemWidget( this, scaleBar );
   mainLayout->addWidget( itemPropertiesWidget );
 
+  mSegmentSizeRadioGroup.addButton( mFixedSizeRadio );
+  mSegmentSizeRadioGroup.addButton( mFitWidthRadio );
+  connect( &mSegmentSizeRadioGroup, SIGNAL( buttonClicked( QAbstractButton* ) ), this, SLOT( segmentSizeRadioChanged( QAbstractButton* ) ) );
+
   blockMemberSignals( true );
 
   //style combo box
@@ -221,6 +225,23 @@ void QgsComposerScaleBarWidget::setGuiElements()
   //units
   mUnitsComboBox->setCurrentIndex( mUnitsComboBox->findData(( int )mComposerScaleBar->units() ) );
 
+  if ( mComposerScaleBar->segmentSizeMode() == QgsComposerScaleBar::SegmentSizeFixed )
+  {
+    mFixedSizeRadio->setChecked( true );
+    mSegmentSizeSpinBox->setEnabled( true );
+    mMinWidthSpinBox->setEnabled( false );
+    mMaxWidthSpinBox->setEnabled( false );
+  }
+  else /*if(mComposerScaleBar->segmentSizeMode() == QgsComposerScaleBar::SegmentSizeFitWidth)*/
+  {
+    mFitWidthRadio->setChecked( true );
+    mSegmentSizeSpinBox->setEnabled( false );
+    mMinWidthSpinBox->setEnabled( true );
+    mMaxWidthSpinBox->setEnabled( true );
+  }
+  mMinWidthSpinBox->setValue( mComposerScaleBar->minBarWidth() );
+  mMaxWidthSpinBox->setValue( mComposerScaleBar->maxBarWidth() );
+
   blockMemberSignals( false );
 }
 
@@ -621,6 +642,7 @@ void QgsComposerScaleBarWidget::blockMemberSignals( bool block )
   mFillColorButton->blockSignals( block );
   mFillColor2Button->blockSignals( block );
   mStrokeColorButton->blockSignals( block );
+  mSegmentSizeRadioGroup.blockSignals( block );
 }
 
 void QgsComposerScaleBarWidget::connectUpdateSignal()
@@ -664,3 +686,61 @@ void QgsComposerScaleBarWidget::on_mLineCapStyleCombo_currentIndexChanged( int i
   mComposerScaleBar->setLineCapStyle( mLineCapStyleCombo->penCapStyle() );
   mComposerScaleBar->endCommand();
 }
+
+void QgsComposerScaleBarWidget::segmentSizeRadioChanged( QAbstractButton* radio )
+{
+  bool fixedSizeMode = radio == mFixedSizeRadio;
+  mMinWidthSpinBox->setEnabled( !fixedSizeMode );
+  mMaxWidthSpinBox->setEnabled( !fixedSizeMode );
+  mSegmentSizeSpinBox->setEnabled( fixedSizeMode );
+
+  if ( !mComposerScaleBar )
+  {
+    return;
+  }
+
+  mComposerScaleBar->beginCommand( tr( "Scalebar segment size mode" ), QgsComposerMergeCommand::ScaleBarSegmentSize );
+  disconnectUpdateSignal();
+  if ( mFixedSizeRadio->isChecked() )
+  {
+    mComposerScaleBar->setSegmentSizeMode( QgsComposerScaleBar::SegmentSizeFixed );
+    mComposerScaleBar->setNumUnitsPerSegment( mSegmentSizeSpinBox->value() );
+  }
+  else /*if(mFitWidthRadio->isChecked())*/
+  {
+    mComposerScaleBar->setSegmentSizeMode( QgsComposerScaleBar::SegmentSizeFitWidth );
+  }
+  mComposerScaleBar->update();
+  connectUpdateSignal();
+  mComposerScaleBar->endCommand();
+}
+
+void QgsComposerScaleBarWidget::on_mMinWidthSpinBox_valueChanged( int )
+{
+  if ( !mComposerScaleBar )
+  {
+    return;
+  }
+
+  mComposerScaleBar->beginCommand( tr( "Scalebar segment size mode" ), QgsComposerMergeCommand::ScaleBarSegmentSize );
+  disconnectUpdateSignal();
+  mComposerScaleBar->setMinBarWidth( mMinWidthSpinBox->value() );
+  mComposerScaleBar->update();
+  connectUpdateSignal();
+  mComposerScaleBar->endCommand();
+}
+
+void QgsComposerScaleBarWidget::on_mMaxWidthSpinBox_valueChanged( int )
+{
+  if ( !mComposerScaleBar )
+  {
+    return;
+  }
+
+  mComposerScaleBar->beginCommand( tr( "Scalebar segment size mode" ), QgsComposerMergeCommand::ScaleBarSegmentSize );
+  disconnectUpdateSignal();
+  mComposerScaleBar->setMaxBarWidth( mMaxWidthSpinBox->value() );
+  mComposerScaleBar->update();
+  connectUpdateSignal();
+  mComposerScaleBar->endCommand();
+}
diff --git a/src/app/composer/qgscomposerscalebarwidget.h b/src/app/composer/qgscomposerscalebarwidget.h
@@ -54,15 +54,19 @@ class QgsComposerScaleBarWidget: public QgsComposerItemBaseWidget, private Ui::Q
     void on_mUnitsComboBox_currentIndexChanged( int index );
     void on_mLineJoinStyleCombo_currentIndexChanged( int index );
     void on_mLineCapStyleCombo_currentIndexChanged( int index );
+    void on_mMinWidthSpinBox_valueChanged( int i );
+    void on_mMaxWidthSpinBox_valueChanged( int i );
 
   private slots:
     void setGuiElements();
+    void segmentSizeRadioChanged( QAbstractButton*radio );
 
   protected:
     void showEvent( QShowEvent * event ) override;
 
   private:
     QgsComposerScaleBar* mComposerScaleBar;
+    QButtonGroup mSegmentSizeRadioGroup;
 
     void refreshMapComboBox();
     /**Enables/disables the signals of the input gui elements*/
diff --git a/src/core/composer/qgscomposerscalebar.cpp b/src/core/composer/qgscomposerscalebar.cpp
@@ -39,6 +39,9 @@ QgsComposerScaleBar::QgsComposerScaleBar( QgsComposition* composition )
     : QgsComposerItem( composition )
     , mComposerMap( 0 )
     , mNumUnitsPerSegment( 0 )
+    , mSegmentSizeMode( SegmentSizeFixed )
+    , mMinBarWidth( 50 )
+    , mMaxBarWidth( 150 )
     , mFontColor( QColor( 0, 0, 0 ) )
     , mStyle( 0 )
     , mSegmentMillimeters( 0.0 )
@@ -114,6 +117,51 @@ void QgsComposerScaleBar::setNumUnitsPerSegment( double units )
   emit itemChanged();
 }
 
+void QgsComposerScaleBar::setSegmentSizeMode( SegmentSizeMode mode )
+{
+  if ( !mStyle )
+  {
+    mSegmentSizeMode = mode;
+    return;
+  }
+  double width = mStyle->calculateBoxSize().width();
+  mSegmentSizeMode = mode;
+  refreshSegmentMillimeters();
+  double widthAfter = mStyle->calculateBoxSize().width();
+  correctXPositionAlignment( width, widthAfter );
+  emit itemChanged();
+}
+
+void QgsComposerScaleBar::setMinBarWidth( double minWidth )
+{
+  if ( !mStyle )
+  {
+    mMinBarWidth = minWidth;
+    return;
+  }
+  double width = mStyle->calculateBoxSize().width();
+  mMinBarWidth = minWidth;
+  refreshSegmentMillimeters();
+  double widthAfter = mStyle->calculateBoxSize().width();
+  correctXPositionAlignment( width, widthAfter );
+  emit itemChanged();
+}
+
+void QgsComposerScaleBar::setMaxBarWidth( double maxWidth )
+{
+  if ( !mStyle )
+  {
+    mMaxBarWidth = maxWidth;
+    return;
+  }
+  double width = mStyle->calculateBoxSize().width();
+  mMaxBarWidth = maxWidth;
+  refreshSegmentMillimeters();
+  double widthAfter = mStyle->calculateBoxSize().width();
+  correctXPositionAlignment( width, widthAfter );
+  emit itemChanged();
+}
+
 void QgsComposerScaleBar::setNumSegmentsLeft( int nSegmentsLeft )
 {
   if ( !mStyle )
@@ -175,18 +223,65 @@ void QgsComposerScaleBar::invalidateCurrentMap()
   mComposerMap = 0;
 }
 
+// nextNiceNumber(4573.23, d) = 5000 (d=1) -> 4600 (d=10) -> 4580 (d=100) -> 4574 (d=1000) -> etc
+inline double nextNiceNumber( double a, double d = 1 )
+{
+  double s = pow10( floor( log10( a ) ) ) / d;
+  return ceil( a / s ) * s;
+}
+
+// prevNiceNumber(4573.23, d) = 4000 (d=1) -> 4500 (d=10) -> 4570 (d=100) -> 4573 (d=1000) -> etc
+inline double prevNiceNumber( double a, double d = 1 )
+{
+  double s = pow10( floor( log10( a ) ) ) / d;
+  return floor( a / s ) * s;
+}
+
 void QgsComposerScaleBar::refreshSegmentMillimeters()
 {
   if ( mComposerMap )
   {
-    //get extent of composer map
-    QgsRectangle composerMapRect = *( mComposerMap->currentMapExtent() );
-
     //get mm dimension of composer map
     QRectF composerItemRect = mComposerMap->rect();
 
-    //calculate size depending on mNumUnitsPerSegment
-    mSegmentMillimeters = composerItemRect.width() / mapWidth() * mNumUnitsPerSegment;
+    if ( mSegmentSizeMode == SegmentSizeFixed )
+    {
+      //calculate size depending on mNumUnitsPerSegment
+      mSegmentMillimeters = composerItemRect.width() / mapWidth() * mNumUnitsPerSegment;
+    }
+    else /*if(mSegmentSizeMode == SegmentSizeFitWidth)*/
+    {
+      if ( mMaxBarWidth < mMinBarWidth )
+      {
+        mSegmentMillimeters = 0;
+      }
+      else
+      {
+        double nSegments = ( mNumSegmentsLeft != 0 ) + mNumSegments;
+        // unitsPerSegments which fit minBarWidth resp. maxBarWidth
+        double minUnitsPerSeg = ( mMinBarWidth * mapWidth() ) / ( nSegments * composerItemRect.width() );
+        double maxUnitsPerSeg = ( mMaxBarWidth * mapWidth() ) / ( nSegments * composerItemRect.width() );
+
+        // Start with coarsest "nice" number closest to minUnitsPerSeg resp
+        // maxUnitsPerSeg, then proceed to finer numbers as long as neither
+        // lowerNiceUnitsPerSeg nor upperNiceUnitsPerSeg are are in
+        // [minUnitsPerSeg, maxUnitsPerSeg]
+        double lowerNiceUnitsPerSeg = nextNiceNumber( minUnitsPerSeg );
+        double upperNiceUnitsPerSeg = prevNiceNumber( maxUnitsPerSeg );
+
+        double d = 1;
+        while ( lowerNiceUnitsPerSeg > maxUnitsPerSeg && upperNiceUnitsPerSeg < minUnitsPerSeg )
+        {
+          d *= 10;
+          lowerNiceUnitsPerSeg = nextNiceNumber( minUnitsPerSeg, d );
+          upperNiceUnitsPerSeg = prevNiceNumber( maxUnitsPerSeg, d );
+        }
+
+        // Pick mNumUnitsPerSegment from {lowerNiceUnitsPerSeg, upperNiceUnitsPerSeg}, use the larger if possible
+        mNumUnitsPerSegment = upperNiceUnitsPerSeg < minUnitsPerSeg ? lowerNiceUnitsPerSeg : upperNiceUnitsPerSeg;
+        mSegmentMillimeters = composerItemRect.width() / mapWidth() * mNumUnitsPerSegment;
+      }
+    }
   }
 }
 
@@ -568,6 +663,9 @@ bool QgsComposerScaleBar::writeXML( QDomElement& elem, QDomDocument & doc ) cons
   composerScaleBarElem.setAttribute( "numSegments", mNumSegments );
   composerScaleBarElem.setAttribute( "numSegmentsLeft", mNumSegmentsLeft );
   composerScaleBarElem.setAttribute( "numUnitsPerSegment", QString::number( mNumUnitsPerSegment ) );
+  composerScaleBarElem.setAttribute( "segmentSizeMode", mSegmentSizeMode );
+  composerScaleBarElem.setAttribute( "minBarWidth", mMinBarWidth );
+  composerScaleBarElem.setAttribute( "maxBarWidth", mMaxBarWidth );
   composerScaleBarElem.setAttribute( "segmentMillimeters", QString::number( mSegmentMillimeters ) );
   composerScaleBarElem.setAttribute( "numMapUnitsPerScaleBarUnit", QString::number( mNumMapUnitsPerScaleBarUnit ) );
   composerScaleBarElem.setAttribute( "font", mFont.toString() );
@@ -646,6 +744,9 @@ bool QgsComposerScaleBar::readXML( const QDomElement& itemElem, const QDomDocume
   mNumSegments = itemElem.attribute( "numSegments", "2" ).toInt();
   mNumSegmentsLeft = itemElem.attribute( "numSegmentsLeft", "0" ).toInt();
   mNumUnitsPerSegment = itemElem.attribute( "numUnitsPerSegment", "1.0" ).toDouble();
+  mSegmentSizeMode = static_cast<SegmentSizeMode>( itemElem.attribute( "segmentSizeMode", "0" ).toInt() );
+  mMinBarWidth = itemElem.attribute( "minBarWidth", "50" ).toInt();
+  mMaxBarWidth = itemElem.attribute( "maxBarWidth", "150" ).toInt();
   mSegmentMillimeters = itemElem.attribute( "segmentMillimeters", "0.0" ).toDouble();
   mNumMapUnitsPerScaleBarUnit = itemElem.attribute( "numMapUnitsPerScaleBarUnit", "1.0" ).toDouble();
   mPen.setWidthF( itemElem.attribute( "outlineWidth", "1.0" ).toDouble() );
diff --git a/src/core/composer/qgscomposerscalebar.h b/src/core/composer/qgscomposerscalebar.h
diff --git a/src/ui/qgscomposerscalebarwidgetbase.ui b/src/ui/qgscomposerscalebarwidgetbase.ui
