HorizontalDrawStrategy Class Reference

#include <rulerstrategies.hh>

Inheritance diagram for HorizontalDrawStrategy:

Collaboration diagram for HorizontalDrawStrategy:

Public Member Functions
double	getMajorTickLength (double percentage) override
double	getDrawAreaSize () override
void	drawOutline (cairo_t *cr, double lineWidth) override
void	drawTickLine (cairo_t *cr, double linePosition, double lineWidth, double lineLength) override
void	drawTickText (cairo_t *cr, const std::string &label, double linePosition, double labelOffset, double labelAlign, double lineLength) override
Public Member Functions inherited from RulerDrawStrategy
void	setAllocatedSize (int newWidth, int height)
int	getWidth () const
int	getHeight () const

Static Public Member Functions
static RulerDrawStrategy::Ptr	create ()

Additional Inherited Members
Public Types inherited from RulerDrawStrategy
using	Ptr = boost::shared_ptr< RulerDrawStrategy >
Static Protected Attributes inherited from RulerDrawStrategy
static constexpr double	LINE_COORD_OFFSET {0.5}
static constexpr double	TEXT_ANCHOR {0.5}

Detailed Description

This class implements the drawing code for a horizontal ruler.

Member Function Documentation

create()

RulerDrawStrategy::Ptr HorizontalDrawStrategy::create ( )

static

Creates a new HorizontalDrawStrategy.

Returns

A new HorizontalDrawStrategy.

{ return RulerDrawStrategy::Ptr(new HorizontalDrawStrategy()); }

Referenced by Ruler::create().

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drawOutline()

void HorizontalDrawStrategy::drawOutline ( cairo_t *  cr, double  lineWidth  )

overridevirtual

Draws the outline around the ruler.

Parameters

cr	Cairo context to draw to.
lineWidth	Width of the outline in pixels.

Implements RulerDrawStrategy.

{
  const int width_  = getWidth();
  const int height_ = getHeight();
 
  cairo_set_line_width(cr, lineWidth);
  const double DRAW_OFFSET = lineWidth * LINE_COORD_OFFSET;
 
  // Draw line along left side of ruler
  cairo_move_to(cr, DRAW_OFFSET, 0);
  cairo_line_to(cr, DRAW_OFFSET, height_);
 
  // Draw line along right side of ruler
  cairo_move_to(cr, width_ - DRAW_OFFSET, 0);
  cairo_line_to(cr, width_ - DRAW_OFFSET, height_);
 
  // Draw thicker border along bottom of ruler
  cairo_move_to(cr, 0, height_ - DRAW_OFFSET);
  cairo_line_to(cr, width_, height_ - DRAW_OFFSET);
 
  // Render all lines
  cairo_stroke(cr);
}

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drawTickLine()

void HorizontalDrawStrategy::drawTickLine ( cairo_t *  cr, double  linePosition, double  lineWidth, double  lineLength  )

overridevirtual

Draws the line for a ruler tick.

Parameters

cr	Cairo context to draw to.
linePosition	Position of the line along the ruler in pixels.
lineWidth	Width of the tick line in pixels.
lineLength	Length of the tick line in pixels.
width	Allocated width for the ruler in pixels.
height	Allocated height for the ruler in pixels.

Implements RulerDrawStrategy.

{
  const int height_ = getHeight();
 
  cairo_set_line_width(cr, lineWidth);
  const double DRAW_OFFSET = lineWidth * LINE_COORD_OFFSET;
 
  // Draw vertical line
  cairo_move_to(cr, linePosition + DRAW_OFFSET, height_);
  cairo_line_to(cr, linePosition + DRAW_OFFSET, height_ - round(lineLength));
  cairo_stroke(cr);
}

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drawTickText()

void HorizontalDrawStrategy::drawTickText ( cairo_t *  cr, const std::string &  label, double  linePosition, double  labelOffset, double  labelAlign, double  lineLength  )

overridevirtual

Draws the label to the right of a tick line.

Parameters

cr	Cairo context to draw to.
label	Text to draw to right of tick line.
linePosition	Position of the line along the ruler in pixels.
labelOffset	Offset between tick line and label in pixels.
labelAlign	Alignment of label along tick line as a fraction of line length.
lineLength	Length of the tick line in pixels.
width	Allocated width for the ruler in pixels.
height	Allocated height for the ruler in pixels.

Implements RulerDrawStrategy.

{
  const int height_ = getHeight();
 
  // Get the extents of the text if it were drawn
  cairo_text_extents_t textExtents;
  cairo_text_extents(cr, label.c_str(), &textExtents);
  // Center the text on the line
  cairo_move_to(cr, linePosition + labelOffset, height_ - labelAlign * lineLength - TEXT_ANCHOR * textExtents.y_bearing);
  cairo_show_text(cr, label.c_str());
}

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getDrawAreaSize()

double HorizontalDrawStrategy::getDrawAreaSize ( )

overridevirtual

Returns the length in pixels along the ruler. For a horizontal ruler, this is its width. For a vertical ruler, this is its height.

Parameters

width	Allocated width for the ruler in pixels.
height	Allocated height for the ruler in pixels.

Returns

The length in pixels along the ruler in pixels.

Implements RulerDrawStrategy.

{ return getWidth(); }

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getMajorTickLength()

double HorizontalDrawStrategy::getMajorTickLength ( double  percentage )

overridevirtual

Returns the length of the major tick lines, given the ruler dimensions.

Parameters

width	Allocated width for the ruler in pixels.
height	Allocated height for the ruler in pixels.
percentage	Percentage of the /p width or /p height to be the length of the major ticks.

Returns

The length of the major tick lines in pixels.

Implements RulerDrawStrategy.

{ return percentage * getHeight(); }

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The documentation for this class was generated from the following files:

• gui/ruler/inc/rulerstrategies.hh
• gui/ruler/src/rulerstrategies.cc