GridLineLimiter Class Reference

Limit the number of grid lines so a bad combination of start/step/stop value will not lead to extremely long delays when the step size is much too small for the start/stop values. More...

#include <GridLineLimiter.h>

Collaboration diagram for GridLineLimiter:

Public Member Functions
	GridLineLimiter ()
	Single constructor. More...
void	limitForXTheta (const Document &document, const Transformation &transformation, const DocumentModelCoords &modelCoords, const MainWindowModel &modelMainWindow, const DocumentModelGridDisplay &modelGrid, double &startX, double &stepX, double &stopX) const
	Limit step value for x/theta coordinate. This is a noop if the maximum grid line limit in MainWindowModel is not exceeded. More...
void	limitForYRadius (const Document &document, const Transformation &transformation, const DocumentModelCoords &modelCoords, const MainWindowModel &modelMainWindow, const DocumentModelGridDisplay &modelGrid, double &startY, double &stepY, double &stopY) const
	Limit step value for y/range coordinate. This is a noop if the maximum grid line limit in MainWindowModel is not exceeded. More...

Detailed Description

Limit the number of grid lines so a bad combination of start/step/stop value will not lead to extremely long delays when the step size is much too small for the start/stop values.

Definition at line 23 of file GridLineLimiter.h.

Constructor & Destructor Documentation

GridLineLimiter()

GridLineLimiter::GridLineLimiter

(

)

Single constructor.

Definition at line 19 of file GridLineLimiter.cpp.

{
}

Member Function Documentation

limitForXTheta()

void GridLineLimiter::limitForXTheta	(	const Document &	document,
		const Transformation &	transformation,
		const DocumentModelCoords &	modelCoords,
		const MainWindowModel &	modelMainWindow,
		const DocumentModelGridDisplay &	modelGrid,
		double &	startX,
		double &	stepX,
		double &	stopX
	)		const

Limit step value for x/theta coordinate. This is a noop if the maximum grid line limit in MainWindowModel is not exceeded.

Definition at line 42 of file GridLineLimiter.cpp.

{
  startX = modelGrid.startX();
  stopX = modelGrid.stopX();
  stepX = modelGrid.stepX();
  int countX = signed (modelGrid.countX());

  bool needReduction = (countX > modelMainWindow.maximumGridLines());

  if (modelCoords.coordScaleXTheta() == COORD_SCALE_LINEAR) {

    // Linear
    if (!needReduction) {
      if (stepX <= 0) {
        stepX = 0;
        needReduction = true;
      } else {
        countX = qFloor (1.0 + (stopX - startX) / stepX);
        needReduction = (countX > modelMainWindow.maximumGridLines());
      }
    }

    if (needReduction) {
      stopX = startX + stepX * (modelMainWindow.maximumGridLines() - 1);
    }

  } else {

    // Log
    if (startX <= 0) {

      // Start value is invalid so override both start and step
      QPointF boundingRectGraphMin, boundingRectGraphMax;
      documentBounds (document,
                      transformation,
                      boundingRectGraphMin,
                      boundingRectGraphMax);

      // Override lower bound
      startX = boundingRectGraphMin.x ();
    }

    if (!needReduction) {
      if (stepX <= 1) {
        stepX = 1;
        needReduction = true;        
      } else {
        countX = qFloor (1.0 + (qLn (stopX) - qLn (startX)) / qLn (stepX));
        needReduction = (countX > modelMainWindow.maximumGridLines());
      }
    }

    if (needReduction) {
      stopX = qExp (qLn (startX) + qLn (stepX) * (modelMainWindow.maximumGridLines() - 1));
    }
  }
}

limitForYRadius()

void GridLineLimiter::limitForYRadius	(	const Document &	document,
		const Transformation &	transformation,
		const DocumentModelCoords &	modelCoords,
		const MainWindowModel &	modelMainWindow,
		const DocumentModelGridDisplay &	modelGrid,
		double &	startY,
		double &	stepY,
		double &	stopY
	)		const

Limit step value for y/range coordinate. This is a noop if the maximum grid line limit in MainWindowModel is not exceeded.

Definition at line 107 of file GridLineLimiter.cpp.

{
  startY = modelGrid.startY();
  stopY = modelGrid.stopY();
  stepY = modelGrid.stepY();
  int countY = signed (modelGrid.countY());

  bool needReduction = (countY > modelMainWindow.maximumGridLines());

  if (modelCoords.coordScaleYRadius() == COORD_SCALE_LINEAR) {

    // Linear
    if (!needReduction) {
      if (stepY <= 0) {
        stepY = 0;
        needReduction = true;        
      } else {
        countY = qFloor (1.0 + (stopY - startY) / stepY);
        needReduction = (countY > modelMainWindow.maximumGridLines());
      }
    }

    if (needReduction) {
      stopY = startY + stepY * (modelMainWindow.maximumGridLines() - 1);
    }

  } else {

    // Log
    if (startY <= 0) {

      // Start value is invalid so override both start and step
      QPointF boundingRectGraphMin, boundingRectGraphMax;
      documentBounds (document,
                      transformation,
                      boundingRectGraphMin,
                      boundingRectGraphMax);

      // Override lower bound
      startY = boundingRectGraphMin.y ();
    }

    if (!needReduction) {
      if (stepY <= 1) {
        stepY = 1;
        needReduction = true;        
      } else {
        countY = qFloor (1.0 + (qLn (stopY) - qLn (startY)) / qLn (stepY));
        needReduction = (countY > modelMainWindow.maximumGridLines());
      }
    }

    if (needReduction) {
      stopY = qExp (qLn (startY) + qLn (stepY) * (modelMainWindow.maximumGridLines() - 1));
    }
  }
}

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

• Grid/GridLineLimiter.h
• Grid/GridLineLimiter.cpp