void QgsDecorationScaleBar::render( QPainter * theQPainter )
{
QgsMapCanvas* canvas = QgisApp::instance()->mapCanvas();
int myBufferSize = 1; //softcode this later
//Get canvas dimensions
int myCanvasHeight = theQPainter->device()->height();
int myCanvasWidth = theQPainter->device()->width();
//Get map units per pixel. This can be negative at times (to do with
//projections) and that just confuses the rest of the code in this
//function, so force to a positive number.
double myMapUnitsPerPixelDouble = qAbs( canvas->mapUnitsPerPixel() );
double myActualSize = mPreferredSize;
// Exit if the canvas width is 0 or layercount is 0 or QGIS will freeze
int myLayerCount = canvas->layerCount();
if ( !myLayerCount || !myCanvasWidth || !myMapUnitsPerPixelDouble )
return;
//Large if statement which determines whether to render the scale bar
if ( enabled() )
{
// Hard coded sizes
int myMajorTickSize = 8;
int myTextOffsetX = 3;
int myMargin = 20;
QSettings settings;
QGis::UnitType myPreferredUnits = QGis::fromLiteral( settings.value( "/qgis/measure/displayunits", QGis::toLiteral( QGis::Meters ) ).toString() );
QGis::UnitType myMapUnits = canvas->mapUnits();
// Adjust units meter/feet/... or vice versa
myMapUnitsPerPixelDouble *= QGis::fromUnitToUnitFactor( myMapUnits, myPreferredUnits );
myMapUnits = myPreferredUnits;
//Calculate size of scale bar for preferred number of map units
double myScaleBarWidth = mPreferredSize / myMapUnitsPerPixelDouble;
//If scale bar is very small reset to 1/4 of the canvas wide
if ( myScaleBarWidth < 30 )
{
myScaleBarWidth = myCanvasWidth / 4.0; // pixels
myActualSize = myScaleBarWidth * myMapUnitsPerPixelDouble; // map units
}
//if scale bar is more than half the canvas wide keep halving until not
while ( myScaleBarWidth > myCanvasWidth / 3.0 )
{
myScaleBarWidth = myScaleBarWidth / 3;
}
myActualSize = myScaleBarWidth * myMapUnitsPerPixelDouble;
// Work out the exponent for the number - e.g, 1234 will give 3,
// and .001234 will give -3
double myPowerOf10 = floor( log10( myActualSize ) );
// snap to integer < 10 times power of 10
if ( mSnapping )
{
double scaler = pow( 10.0, myPowerOf10 );
myActualSize = qRound( myActualSize / scaler ) * scaler;
myScaleBarWidth = myActualSize / myMapUnitsPerPixelDouble;
}
//Get type of map units and set scale bar unit label text
QString myScaleBarUnitLabel;
switch ( myMapUnits )
{
case QGis::Meters:
if ( myActualSize > 1000.0 )
{
myScaleBarUnitLabel = tr( " km" );
myActualSize = myActualSize / 1000;
}
else if ( myActualSize < 0.01 )
{
myScaleBarUnitLabel = tr( " mm" );
myActualSize = myActualSize * 1000;
}
else if ( myActualSize < 0.1 )
{
myScaleBarUnitLabel = tr( " cm" );
myActualSize = myActualSize * 100;
}
else
myScaleBarUnitLabel = tr( " m" );
break;
case QGis::Feet:
if ( myActualSize > 5280.0 ) //5280 feet to the mile
{
myScaleBarUnitLabel = tr( " miles" );
// Adjust scale bar width to get even numbers
myActualSize = myActualSize / 5000;
myScaleBarWidth = ( myScaleBarWidth * 5280 ) / 5000;
}
else if ( myActualSize == 5280.0 ) //5280 feet to the mile
{
myScaleBarUnitLabel = tr( " mile" );
// Adjust scale bar width to get even numbers
myActualSize = myActualSize / 5000;
myScaleBarWidth = ( myScaleBarWidth * 5280 ) / 5000;
}
else if ( myActualSize < 1 )
{
myScaleBarUnitLabel = tr( " inches" );
myActualSize = myActualSize * 10;
myScaleBarWidth = ( myScaleBarWidth * 10 ) / 12;
}
else if ( myActualSize == 1.0 )
{
myScaleBarUnitLabel = tr( " foot" );
}
else
{
myScaleBarUnitLabel = tr( " feet" );
}
break;
case QGis::Degrees:
if ( myActualSize == 1.0 )
myScaleBarUnitLabel = tr( " degree" );
else
myScaleBarUnitLabel = tr( " degrees" );
break;
case QGis::UnknownUnit:
myScaleBarUnitLabel = tr( " unknown" );
default:
QgsDebugMsg( QString( "Error: not picked up map units - actual value = %1" ).arg( myMapUnits ) );
}
//Set font and calculate width of unit label
int myFontSize = 10; //we use this later for buffering
QFont myFont( "helvetica", myFontSize );
theQPainter->setFont( myFont );
QFontMetrics myFontMetrics( myFont );
double myFontWidth = myFontMetrics.width( myScaleBarUnitLabel );
double myFontHeight = myFontMetrics.height();
//Set the maximum label
QString myScaleBarMaxLabel = QLocale::system().toString( myActualSize );
//Calculate total width of scale bar and label
double myTotalScaleBarWidth = myScaleBarWidth + myFontWidth;
//determine the origin of scale bar depending on placement selected
int myOriginX = myMargin;
int myOriginY = myMargin;
switch ( mPlacementIndex )
{
case 0: // Bottom Left
myOriginX = myMargin;
myOriginY = myCanvasHeight - myMargin;
break;
case 1: // Top Left
myOriginX = myMargin;
myOriginY = myMargin;
break;
case 2: // Top Right
myOriginX = myCanvasWidth - (( int ) myTotalScaleBarWidth ) - myMargin;
myOriginY = myMargin;
break;
case 3: // Bottom Right
myOriginX = myCanvasWidth - (( int ) myTotalScaleBarWidth ) - myMargin;
myOriginY = myCanvasHeight - myMargin;
break;
default:
QgsDebugMsg( "Unable to determine where to put scale bar so defaulting to top left" );
}
//Set pen to draw with
QPen myForegroundPen( mColor, 2 );
QPen myBackgroundPen( Qt::white, 4 );
//Cast myScaleBarWidth to int for drawing
int myScaleBarWidthInt = ( int ) myScaleBarWidth;
//Create array of vertices for scale bar depending on style
switch ( mStyleIndex )
{
case 0: // Tick Down
{
QPolygon myTickDownArray( 4 );
//draw a buffer first so bar shows up on dark images
theQPainter->setPen( myBackgroundPen );
myTickDownArray.putPoints( 0, 4,
myOriginX, myOriginY + myMajorTickSize,
myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY + myMajorTickSize
);
theQPainter->drawPolyline( myTickDownArray );
//now draw the bar itself in user selected color
theQPainter->setPen( myForegroundPen );
myTickDownArray.putPoints( 0, 4,
myOriginX, myOriginY + myMajorTickSize,
myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY + myMajorTickSize
);
theQPainter->drawPolyline( myTickDownArray );
break;
}
case 1: // tick up
{
QPolygon myTickUpArray( 4 );
//draw a buffer first so bar shows up on dark images
theQPainter->setPen( myBackgroundPen );
myTickUpArray.putPoints( 0, 4,
myOriginX, myOriginY,
myOriginX, myOriginY + myMajorTickSize,
myScaleBarWidthInt + myOriginX, myOriginY + myMajorTickSize,
myScaleBarWidthInt + myOriginX, myOriginY
);
theQPainter->drawPolyline( myTickUpArray );
//now draw the bar itself in user selected color
theQPainter->setPen( myForegroundPen );
myTickUpArray.putPoints( 0, 4,
myOriginX, myOriginY,
myOriginX, myOriginY + myMajorTickSize,
myScaleBarWidthInt + myOriginX, myOriginY + myMajorTickSize,
myScaleBarWidthInt + myOriginX, myOriginY
);
theQPainter->drawPolyline( myTickUpArray );
break;
}
case 2: // Bar
{
QPolygon myBarArray( 2 );
//draw a buffer first so bar shows up on dark images
theQPainter->setPen( myBackgroundPen );
myBarArray.putPoints( 0, 2,
myOriginX, myOriginY + ( myMajorTickSize / 2 ),
myScaleBarWidthInt + myOriginX, myOriginY + ( myMajorTickSize / 2 )
);
theQPainter->drawPolyline( myBarArray );
//now draw the bar itself in user selected color
theQPainter->setPen( myForegroundPen );
myBarArray.putPoints( 0, 2,
myOriginX, myOriginY + ( myMajorTickSize / 2 ),
myScaleBarWidthInt + myOriginX, myOriginY + ( myMajorTickSize / 2 )
);
theQPainter->drawPolyline( myBarArray );
break;
}
case 3: // box
{
// Want square corners for a box
myBackgroundPen.setJoinStyle( Qt::MiterJoin );
myForegroundPen.setJoinStyle( Qt::MiterJoin );
QPolygon myBoxArray( 5 );
//draw a buffer first so bar shows up on dark images
theQPainter->setPen( myBackgroundPen );
myBoxArray.putPoints( 0, 5,
myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY + myMajorTickSize,
myOriginX, myOriginY + myMajorTickSize,
myOriginX, myOriginY
);
theQPainter->drawPolyline( myBoxArray );
//now draw the bar itself in user selected color
theQPainter->setPen( myForegroundPen );
theQPainter->setBrush( QBrush( mColor, Qt::SolidPattern ) );
int midPointX = myScaleBarWidthInt / 2 + myOriginX;
myBoxArray.putPoints( 0, 5,
myOriginX, myOriginY,
midPointX, myOriginY,
midPointX, myOriginY + myMajorTickSize,
myOriginX, myOriginY + myMajorTickSize,
myOriginX, myOriginY
);
theQPainter->drawPolygon( myBoxArray );
theQPainter->setBrush( Qt::NoBrush );
myBoxArray.putPoints( 0, 5,
midPointX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY,
myScaleBarWidthInt + myOriginX, myOriginY + myMajorTickSize,
midPointX, myOriginY + myMajorTickSize,
midPointX, myOriginY
);
theQPainter->drawPolygon( myBoxArray );
break;
}
default:
QgsDebugMsg( "Unknown style" );
}
//Do actual drawing of scale bar
//
//Do drawing of scale bar text
//
QColor myBackColor = Qt::white;
QColor myForeColor = Qt::black;
//Draw the minimum label buffer
theQPainter->setPen( myBackColor );
myFontWidth = myFontMetrics.width( "0" );
myFontHeight = myFontMetrics.height();
for ( int i = 0 - myBufferSize; i <= myBufferSize; i++ )
{
for ( int j = 0 - myBufferSize; j <= myBufferSize; j++ )
{
theQPainter->drawText( int( i + ( myOriginX - ( myFontWidth / 2 ) ) ),
int( j + ( myOriginY - ( myFontHeight / 4 ) ) ),
"0" );
}
}
//Draw minimum label
theQPainter->setPen( myForeColor );
theQPainter->drawText(
int( myOriginX - ( myFontWidth / 2 ) ),
int( myOriginY - ( myFontHeight / 4 ) ),
"0"
);
//
//Draw maximum label
//
theQPainter->setPen( myBackColor );
myFontWidth = myFontMetrics.width( myScaleBarMaxLabel );
myFontHeight = myFontMetrics.height();
//first the buffer
for ( int i = 0 - myBufferSize; i <= myBufferSize; i++ )
{
for ( int j = 0 - myBufferSize; j <= myBufferSize; j++ )
{
theQPainter->drawText( int( i + ( myOriginX + myScaleBarWidthInt - ( myFontWidth / 2 ) ) ),
int( j + ( myOriginY - ( myFontHeight / 4 ) ) ),
myScaleBarMaxLabel );
}
}
//then the text itself
theQPainter->setPen( myForeColor );
theQPainter->drawText(
int( myOriginX + myScaleBarWidthInt - ( myFontWidth / 2 ) ),
int( myOriginY - ( myFontHeight / 4 ) ),
myScaleBarMaxLabel
);
//
//Draw unit label
//
theQPainter->setPen( myBackColor );
//first the buffer
for ( int i = 0 - myBufferSize; i <= myBufferSize; i++ )
{
for ( int j = 0 - myBufferSize; j <= myBufferSize; j++ )
{
theQPainter->drawText( i + ( myOriginX + myScaleBarWidthInt + myTextOffsetX ),
j + ( myOriginY + myMajorTickSize ),
myScaleBarUnitLabel );
}
}
//then the text itself
theQPainter->setPen( myForeColor );
theQPainter->drawText(
( myOriginX + myScaleBarWidthInt + myTextOffsetX ), ( myOriginY + myMajorTickSize ),
myScaleBarUnitLabel
);
}
}
bool QgsDecorationNorthArrow::calculateNorthDirection()
{
QgsMapCanvas* mapCanvas = QgisApp::instance()->mapCanvas();
bool goodDirn = false;
// Get the shown extent...
QgsRectangle canvasExtent = mapCanvas->extent();
// ... and all layers extent, ...
QgsRectangle fullExtent = mapCanvas->fullExtent();
// ... and combine
QgsRectangle extent = canvasExtent.intersect( & fullExtent );
// If no layers are added or shown, we can't get any direction
if ( mapCanvas->layerCount() > 0 && ! extent.isEmpty() )
{
QgsCoordinateReferenceSystem outputCRS = mapCanvas->mapRenderer()->destinationCrs();
if ( outputCRS.isValid() && !outputCRS.geographicFlag() )
{
// Use a geographic CRS to get lat/long to work out direction
QgsCoordinateReferenceSystem ourCRS;
ourCRS.createFromOgcWmsCrs( GEO_EPSG_CRS_AUTHID );
assert( ourCRS.isValid() );
QgsCoordinateTransform transform( outputCRS, ourCRS );
QgsPoint p1( extent.center() );
// A point a bit above p1. XXX assumes that y increases up!!
// May need to involve the maptopixel transform if this proves
// to be a problem.
QgsPoint p2( p1.x(), p1.y() + extent.height() * 0.25 );
// project p1 and p2 to geographic coords
try
{
p1 = transform.transform( p1 );
p2 = transform.transform( p2 );
}
catch ( QgsCsException &e )
{
Q_UNUSED( e );
// just give up
QgsDebugMsg( "North Arrow: Transformation error, quitting" );
return false;
}
// Work out the value of the initial heading one takes to go
// from point p1 to point p2. The north direction is then that
// many degrees anti-clockwise or vertical.
// Take some care to not divide by zero, etc, and ensure that we
// get sensible results for all possible values for p1 and p2.
goodDirn = true;
double angle = 0.0;
// convert to radians for the equations below
p1.multiply( PI / 180.0 );
p2.multiply( PI / 180.0 );
double y = sin( p2.x() - p1.x() ) * cos( p2.y() );
double x = cos( p1.y() ) * sin( p2.y() ) -
sin( p1.y() ) * cos( p2.y() ) * cos( p2.x() - p1.x() );
// Use TOL to decide if the quotient is big enough.
// Both x and y can be very small, if heavily zoomed
// For small y/x, we set directly angle 0. Not sure
// if this is needed.
if ( y > 0.0 )
{
if ( x > 0.0 && ( y / x ) > TOL )
angle = atan( y / x );
else if ( x < 0.0 && ( y / x ) < -TOL )
angle = PI - atan( -y / x );
else
angle = 0.5 * PI;
}
else if ( y < 0.0 )
{
if ( x > 0.0 && ( y / x ) < -TOL )
angle = -atan( -y / x );
else if ( x < 0.0 && ( y / x ) > TOL )
angle = atan( y / x ) - PI;
else
angle = 1.5 * PI;
}
else
{
if ( x > TOL )
angle = 0.0;
else if ( x < -TOL )
angle = PI;
else
{
angle = 0.0; // p1 = p2
goodDirn = false;
}
}
// And set the angle of the north arrow. Perhaps do something
// different if goodDirn = false.
mRotationInt = qRound( fmod( 360.0 - angle * 180.0 / PI, 360.0 ) );
}
else
{
// For geographic CRS and for when there are no layers, set the
// direction back to the default
mRotationInt = 0;
}
}
return goodDirn;
}
