add option to draw intermediate grid lines

resources/forms/mainWindow.ui

@@ -1686,6 +1686,22 @@
     <string>Reset grid size</string>
    </property>
   </action>
+  <action name="actionDrawIntermediateGridLines">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="icon">
+    <iconset resource="../OpenBoard.qrc">
+     <normaloff>:/images/minus.svg</normaloff>
+     <normalon>:/images/save.svg</normalon>:/images/minus.svg</iconset>
+   </property>
+   <property name="text">
+    <string>Draw intermediate grid lines</string>
+   </property>
+   <property name="toolTip">
+    <string>Draw intermediate grid lines</string>
+   </property>
+  </action>
  </widget>
  <resources>
   <include location="../OpenBoard.qrc"/>

src/adaptors/UBSvgSubsetAdaptor.cpp

@@ -469,6 +469,14 @@ UBGraphicsScene* UBSvgSubsetAdaptor::UBSvgSubsetReader::loadScene(UBDocumentProx
 
                         mScene->setBackgroundGridSize(gridSize);
                     }
+
+                    QStringRef ubIntermediateLines = mXmlReader.attributes().value(mNamespaceUri, "intermediate-lines");
+
+                    if (!ubIntermediateLines.isNull()) {
+                        bool intermediateLines = ubIntermediateLines.toInt();
+
+                        mScene->setIntermediateLines(intermediateLines);
+                    }
                 }
 
                 QStringRef ubRuledBackground = mXmlReader.attributes().value(mNamespaceUri, "ruled-background");
@@ -484,6 +492,14 @@ UBGraphicsScene* UBSvgSubsetAdaptor::UBSvgSubsetReader::loadScene(UBDocumentProx
 
                         mScene->setBackgroundGridSize(gridSize);
                     }
+
+                    QStringRef ubIntermediateLines = mXmlReader.attributes().value(mNamespaceUri, "intermediate-lines");
+
+                    if (!ubIntermediateLines.isNull()) {
+                        bool intermediateLines = ubIntermediateLines.toInt();
+
+                        mScene->setIntermediateLines(intermediateLines);
+                    }
                 }
 
                 UBPageBackground bg;
@@ -1140,8 +1156,10 @@ void UBSvgSubsetAdaptor::UBSvgSubsetWriter::writeSvgElement(UBDocumentProxy* pro
 
     if (crossedBackground || ruledBackground) {
         int gridSize = mScene->backgroundGridSize();
+        bool intermediateLines = mScene->intermediateLines();
 
         mXmlWriter.writeAttribute(UBSettings::uniboardDocumentNamespaceUri, "grid-size", QString::number(gridSize));
+        mXmlWriter.writeAttribute(UBSettings::uniboardDocumentNamespaceUri, "intermediate-lines", QString::number(intermediateLines));
     }
 
     QDesktopWidget* desktop = UBApplication::desktop();

src/board/UBBoardView.cpp

@@ -1629,6 +1629,7 @@ void UBBoardView::drawBackground (QPainter *painter, const QRectF &rect)
         }
 
         qreal gridSize = scene()->backgroundGridSize();
+        bool intermediateLines = scene()->intermediateLines();
 
         painter->setPen (bgCrossColor);
 
@@ -1647,6 +1648,22 @@ void UBBoardView::drawBackground (QPainter *painter, const QRectF &rect)
             {
                 painter->drawLine (xPos, rect.y (), xPos, rect.y () + rect.height ());
             }
+
+            if (intermediateLines) {
+                QColor intermediateColor = bgCrossColor;
+                intermediateColor.setAlphaF(0.5 * bgCrossColor.alphaF());
+                painter->setPen(intermediateColor);
+
+                for (qreal yPos = firstY - gridSize/2; yPos < rect.y () + rect.height (); yPos += gridSize)
+                {
+                    painter->drawLine (rect.x (), yPos, rect.x () + rect.width (), yPos);
+                }
+
+                for (qreal xPos = firstX - gridSize/2; xPos < rect.x () + rect.width (); xPos += gridSize)
+                {
+                    painter->drawLine (xPos, rect.y (), xPos, rect.y () + rect.height ());
+                }
+            }
         }
 
         if (scene() && scene()->pageBackground() == UBPageBackground::ruled)
@@ -1657,6 +1674,17 @@ void UBBoardView::drawBackground (QPainter *painter, const QRectF &rect)
             {
                 painter->drawLine (rect.x (), yPos, rect.x () + rect.width (), yPos);
             }
+
+            if (intermediateLines) {
+                QColor intermediateColor = bgCrossColor;
+                intermediateColor.setAlphaF(0.5 * bgCrossColor.alphaF());
+                painter->setPen(intermediateColor);
+
+                for (qreal yPos = firstY - gridSize/2; yPos < rect.y () + rect.height (); yPos += gridSize)
+                {
+                    painter->drawLine (rect.x (), yPos, rect.x () + rect.width (), yPos);
+                }
+            }
         }
     }
 

src/core/UBSettings.cpp

@@ -50,6 +50,7 @@ int UBSettings::crossSize = 24;
 int UBSettings::defaultCrossSize = 24;
 int UBSettings::minCrossSize = 12;
 int UBSettings::maxCrossSize = 96; //TODO: user-settable?
+bool UBSettings::intermediateLines = false;
 int UBSettings::colorPaletteSize = 5;
 int UBSettings::objectFrameWidth = 20;
 int UBSettings::boardMargin = 10;

src/core/UBSettings.h

@@ -191,6 +191,7 @@ class UBSettings : public QObject
         static int defaultCrossSize;
         static int minCrossSize;
         static int maxCrossSize;
+        static bool intermediateLines;
 
         static int colorPaletteSize;
         static int objectFrameWidth;

src/domain/UBGraphicsScene.cpp

@@ -359,6 +359,7 @@ UBGraphicsScene::UBGraphicsScene(UBDocumentProxy* parent, bool enableUndoRedoSta
     }
 
     mBackgroundGridSize = UBSettings::settings()->crossSize;
+    mIntermediateLines = UBSettings::settings()->intermediateLines;
 
 //    Just for debug. Do not delete please
 //    connect(this, SIGNAL(selectionChanged()), this, SLOT(selectionChangedProcessing()));
@@ -1155,6 +1156,15 @@ void UBGraphicsScene::setBackgroundGridSize(int pSize)
     }
 }
 
+void UBGraphicsScene::setIntermediateLines(bool checked)
+{
+    mIntermediateLines = checked;
+    setModified(true);
+
+    foreach(QGraphicsView* view, views())
+        view->resetCachedContent();
+}
+
 void UBGraphicsScene::setDrawingMode(bool bModeDesktop)
 {
     mIsDesktopMode = bModeDesktop;

src/domain/UBGraphicsScene.h

@@ -230,6 +230,11 @@ class UBGraphicsScene: public UBCoreGraphicsScene, public UBItem
             return mBackgroundGridSize;
         }
 
+        bool intermediateLines() const
+        {
+            return mIntermediateLines;
+        }
+
         bool hasBackground()
         {
             return (mBackgroundObject != 0);
@@ -359,6 +364,7 @@ public slots:
         void setBackground(bool pIsDark, UBPageBackground pBackground);
         void setBackgroundZoomFactor(qreal zoom);
         void setBackgroundGridSize(int pSize);
+        void setIntermediateLines(bool checked);
         void setDrawingMode(bool bModeDesktop);
         void deselectAllItems();
 
@@ -442,6 +448,7 @@ public slots:
         bool mDarkBackground;
         UBPageBackground mPageBackground;
         int mBackgroundGridSize;
+        bool mIntermediateLines;
 
         bool mIsDesktopMode;
         qreal mZoomFactor;

src/gui/UBBackgroundPalette.cpp

@@ -48,6 +48,7 @@ void UBBackgroundPalette::init()
     mSlider->setTracking(true); // valueChanged() is emitted during movement and not just upon releasing the slider
 
     mSliderLabel = new QLabel(tr("Grid size"));
+    mIntermediateLinesLabel = new QLabel(tr("Draw intermediate grid lines"));
 
     mResetDefaultGridSizeButton = createPaletteButton(UBApplication::mainWindow->actionDefaultGridSize, this);
     mResetDefaultGridSizeButton->setFixedSize(24,24);
@@ -55,11 +56,22 @@ void UBBackgroundPalette::init()
 
     connect(UBApplication::mainWindow->actionDefaultGridSize, SIGNAL(triggered()), this, SLOT(defaultBackgroundGridSize()));
 
+    mDrawIntermediateLinesCheckBox = createPaletteButton(UBApplication::mainWindow->actionDrawIntermediateGridLines, this);
+    mDrawIntermediateLinesCheckBox->setFixedSize(24,24);
+    mDrawIntermediateLinesCheckBox->setCheckable(true);
+    mActions << UBApplication::mainWindow->actionDrawIntermediateGridLines;
+    mButtons.removeLast(); // don't add to button group
+
+    connect(UBApplication::mainWindow->actionDrawIntermediateGridLines, SIGNAL(toggled(bool)), this, SLOT(toggleIntermediateLines(bool)));
+
     mBottomLayout->addSpacing(16);
     mBottomLayout->addWidget(mSliderLabel);
     mBottomLayout->addWidget(mSlider);
     mBottomLayout->addWidget(mResetDefaultGridSizeButton);
     mBottomLayout->addSpacing(16);
+    mBottomLayout->addWidget(mIntermediateLinesLabel);
+    mBottomLayout->addWidget(mDrawIntermediateLinesCheckBox);
+    mBottomLayout->addSpacing(16);
 
     updateLayout();
 }
@@ -137,6 +149,8 @@ void UBBackgroundPalette::showEvent(QShowEvent* event)
     connect(mSlider, SIGNAL(valueChanged(int)),
             this, SLOT(sliderValueChanged(int)));
 
+    mDrawIntermediateLinesCheckBox->setChecked(UBApplication::boardController->activeScene()->intermediateLines());
+
     QWidget::showEvent(event);
 }
 
@@ -152,6 +166,12 @@ void UBBackgroundPalette::defaultBackgroundGridSize()
     sliderValueChanged(UBSettings::settings()->defaultCrossSize);
 }
 
+void UBBackgroundPalette::toggleIntermediateLines(bool checked)
+{
+    UBApplication::boardController->activeScene()->setIntermediateLines(checked);
+    UBSettings::settings()->intermediateLines = checked; // since this function is called (indirectly, by refresh) when we switch scenes, the settings will always have the current scene's value.
+}
+
 void UBBackgroundPalette::backgroundChanged()
 {
     bool dark = UBApplication::boardController->activeScene()->isDarkBackground();

src/gui/UBBackgroundPalette.h

@@ -28,6 +28,7 @@ class UBBackgroundPalette : public UBActionPalette
     protected slots:
         void sliderValueChanged(int value);
         void defaultBackgroundGridSize();
+        void toggleIntermediateLines(bool checked);
 
     protected:
         virtual void updateLayout();
@@ -40,8 +41,9 @@ class UBBackgroundPalette : public UBActionPalette
 
         QSlider* mSlider;
         QLabel* mSliderLabel;
+        QLabel* mIntermediateLinesLabel;
         UBActionPaletteButton* mResetDefaultGridSizeButton;
-
+        UBActionPaletteButton* mDrawIntermediateLinesCheckBox;
 
 };