src/coordcache.h

   1 // -*- C++ -*-
   2 /* \file coordcache.h
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author André Pönitz
   7  *
   8  * Full author contact details are available in file CREDITS.
   9  */
  10
  11 #ifndef COORDCACHE_H
  12 #define COORDCACHE_H
  13
  14 class InsetBase;
  15 class LyXText;
  16 class MathArray;
  17 class Paragraph;
  18
  19 #include "support/types.h"
  20
  21 #include <boost/assert.hpp>
  22
  23 #include <map>
  24
  25 void lyxbreaker(void const * data, const char * hint, int size);
  26
  27 class Point {
  28 public:
  29         Point()
  30                 : x_(0), y_(0)
  31         {}
  32
  33         Point(int x, int y) : x_(x), y_(y)
  34         {
  35                 BOOST_ASSERT(x > -3000);
  36                 BOOST_ASSERT(x <  4000);
  37                 BOOST_ASSERT(y > -3000);
  38                 BOOST_ASSERT(y <  4000);
  39         }
  40
  41         int x_, y_;
  42 };
  43
  44
  45 template <class T> class CoordCacheBase {
  46 public:
  47         void clear()
  48         {
  49                 data_.clear();
  50         }
  51
  52         void add(T const * thing, int x, int y)
  53         {
  54                 data_[thing] = Point(x, y);
  55         }
  56
  57         int x(T const * thing) const
  58         {
  59                 check(thing, "x");
  60                 return data_.find(thing)->second.x_;
  61         }
  62
  63         int y(T const * thing) const
  64         {
  65                 check(thing, "y");
  66                 return data_.find(thing)->second.y_;
  67         }
  68
  69         Point xy(T const * thing) const
  70         {
  71                 check(thing, "xy");
  72                 return data_.find(thing)->second;
  73         }
  74
  75         bool has(T const * thing) const
  76         {
  77                 return data_.find(thing) != data_.end();
  78         }
  79
  80 //      T * find(int x, int y) const
  81 //      {
  82 //              T *
  83 //              cache_type iter
  84 //      }
  85
  86 private:
  87         friend class CoordCache;
  88
  89         void check(T const * thing, char const * hint) const
  90         {
  91                 if (!has(thing))
  92                         lyxbreaker(thing, hint, data_.size());
  93         }
  94
  95         typedef std::map<T const *, Point> cache_type;
  96         cache_type data_;
  97 };
  98
  99 /**
 100  * A global cache that allows us to come from a paragraph in a document
 101  * to a position point on the screen.
 102  * All points cached in this cache are only valid between subsequent
 103  * updated. (x,y) == (0,0) is the upper left screen corner, x increases
 104  * to the right, y increases downwords.
 105  * The cache is built in BufferView::Pimpl::metrics which is called
 106  * from BufferView::Pimpl::update. The individual points are added
 107  * while we paint them. See for instance paintPar in RowPainter.C.
 108  */
 109 class CoordCache {
 110 public:
 111         CoordCache() : updating(false) { }
 112         /// In order to find bugs, we record when we start updating the cache
 113         void startUpdating();
 114         /// When we are done, we record that to help find bugs
 115         void doneUpdating();
 116
 117         void clear();
 118         Point get(LyXText const *, lyx::pit_type);
 119
 120         /// A map from paragraph index number to screen point
 121         typedef std::map<lyx::pit_type, Point> InnerParPosCache;
 122         /// A map from a LyXText to the map of paragraphs to screen points
 123         typedef std::map<LyXText const *, InnerParPosCache> ParPosCache;
 124
 125         /// A map from MathArray to position on the screen
 126         CoordCacheBase<MathArray> & arrays() { BOOST_ASSERT(updating); return arrays_; }
 127         CoordCacheBase<MathArray> const & getArrays() const { return arrays_; }
 128         /// A map from insets to positions on the screen
 129         CoordCacheBase<InsetBase> & insets() { BOOST_ASSERT(updating); return insets_; }
 130         CoordCacheBase<InsetBase> const & getInsets() const { return insets_; }
 131         /// A map from (LyXText, paragraph) pair to screen positions
 132         ParPosCache & parPos() { BOOST_ASSERT(updating); return pars_; }
 133         ParPosCache const & getParPos() const { return pars_; }
 134 private:
 135         CoordCacheBase<MathArray> arrays_;
 136
 137         // all insets
 138         CoordCacheBase<InsetBase> insets_;
 139
 140         // paragraph grouped by owning text
 141         ParPosCache pars_;
 142
 143         /**
 144          * Debugging flag only: Set to true while the cache is being built.
 145          * No changes to the structure are allowed unless we are updating.
 146          */
 147         bool updating;
 148 };
 149
 150 extern CoordCache theCoords;
 151
 152 #endif