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FormatState Class Reference

encapsulates state when wrapping/formatting a text line More...

#include <nodetxtl.h>

List of all members.

Public Member Functions

 FormatState (MILLIPOINT AvailableWidth, BOOL SetPositions, VisibleTextNode *pFirstNode, MILLIPOINT Indent, MILLIPOINT _CharPosOffset, MILLIPOINT _ExtraOnChars, MILLIPOINT _ExtraOnSpaces)
void AdvanceBy (MILLIPOINT Advance, BOOL IsADecimalPoint)
 Account for a char with width CharWidth to be fitted into the current line. See also: TextLine::FindBreakChar for a description of the formatting algorithm used.
BOOL FinishTabSection (VisibleTextNode *pLastFormattedNode, BOOL IsLastTabSection)
 This routine is called when a tab or the end of the line is encountered, so the text after the previous tab (or the start of the line) can be finally formatted. The Width/Advance of the Tab is always set and if SetCharPositions is TRUE, then all the character positions are set.
BOOL IsAvailable (MILLIPOINT CharWidth, BOOL IsATab, BOOL IsADecimalPoint)
 Test whether a char with width CharWidth can be fitted into the current line.

Public Attributes

const BOOL SetCharPositions
const MILLIPOINT FitWidth
VisibleTextNode *const pFirstVTN
const MILLIPOINT CharPosOffset
const MILLIPOINT ExtraOnChars
const MILLIPOINT ExtraOnSpaces
MILLIPOINT Width
TxtTabType ActiveTabType
MILLIPOINT ActiveTabPos
VisibleTextNode * pLastTabVTN
MILLIPOINT AnchorPos
MILLIPOINT RemainingSpace
WCHAR DecimalPointChar
BOOL DecimalPointFound

Detailed Description

encapsulates state when wrapping/formatting a text line

Author:
Martin Wuerthner <xara@mw-software.com>
Date:
21/06/06

Definition at line 198 of file nodetxtl.h.

Constructor & Destructor Documentation

FormatState::FormatState (  MILLIPOINT  AvailableWidth,
BOOL  SetPositions,
VisibleTextNode *  pFirstNode,
MILLIPOINT  Indent,
MILLIPOINT  _CharPosOffset,
MILLIPOINT  _ExtraOnChars,
MILLIPOINT  _ExtraOnSpaces
)  [inline]
 

Definition at line 231 of file nodetxtl.h.

00233                                                                     :
00234         SetCharPositions(SetPositions),
00235         FitWidth(AvailableWidth), pFirstVTN(pFirstNode),
00236         CharPosOffset(_CharPosOffset),
00237         ExtraOnChars(_ExtraOnChars), ExtraOnSpaces(_ExtraOnSpaces),
00238         Width(Indent), ActiveTabType(LeftTab), ActiveTabPos(0), 
00239         pLastTabVTN(NULL), AnchorPos(Indent) {};
    void AdvanceBy(MILLIPOINT Advance, BOOL IsADecimalPoint);

Member Function Documentation

void FormatState::AdvanceBy (  MILLIPOINT  CharWidth,
BOOL  IsADecimalPoint
) 
 

Account for a char with width CharWidth to be fitted into the current line. See also: TextLine::FindBreakChar for a description of the formatting algorithm used.

Author:
Martin Wuerthner <xara@mw-software.com>
Date:
23/06/06
Parameters:
CharWidth - the amount to advance by [INPUTS] IsADecimalPoint - TRUE if the currently active tab is a decimal tab and the character to be formatted is its decimal point character

Definition at line 1133 of file nodetxtl.cpp.

01134 {
01135     // Note: This routine may only update Width and RemainingSpace, otherwise
01136     // the backtracking in IsAvailable() does not work as expected.
01137     if (ActiveTabType == CentreTab && RemainingSpace > 0)
01138     {
01139         MILLIPOINT SpaceToLeftUsed = 0;
01140         // half the width is distributed into RemainingSpace, if it is big enough
01141         if (RemainingSpace >= CharWidth / 2)
01142         {
01143             // half the width fully fits into RemainingSpace
01144             SpaceToLeftUsed = CharWidth / 2;
01145         }
01146         else
01147         {
01148             // does not fit, so use up all of RemainingSpace
01149             SpaceToLeftUsed = RemainingSpace;
01150         }
01151         // distribute some of the character to the left
01152         RemainingSpace -= SpaceToLeftUsed;
01153         // and the remainder to the right
01154         Width += CharWidth - SpaceToLeftUsed;
01155     }
01156     else if ((ActiveTabType == RightTab || (ActiveTabType == DecimalTab && !DecimalPointFound
01157                                             && !IsADecimalPoint))
01158              && RemainingSpace > 0)
01159     {
01160         if (RemainingSpace >= CharWidth) RemainingSpace -= CharWidth;
01161         else
01162         {
01163             Width += CharWidth - RemainingSpace;
01164             RemainingSpace = 0;
01165         }
01166     }
01167     else
01168     {
01169         // We end up here if:
01170         // - the last tab was left tab, or
01171         // - the last tab was a decimal tab and we have already found the decimal point, or
01172         // - the last tab was a decimal tab and this is a decimal point character (NB. - the
01173         //   decimal point is always formatted to the right of the tab position), or, finally,
01174         // - this is any kind of tab and we have no more remaining space to the left of it
01175         // In all these cases, we simply format the character to the right of the current position,
01176         // which is the easiest thing to do anyway
01177         Width += CharWidth;
01178     }
01179 }

BOOL FormatState::FinishTabSection (  VisibleTextNode *  pLastFormattedNode,
BOOL  IsLastTabSection
) 
 

This routine is called when a tab or the end of the line is encountered, so the text after the previous tab (or the start of the line) can be finally formatted. The Width/Advance of the Tab is always set and if SetCharPositions is TRUE, then all the character positions are set.

Author:
Martin Wuerthner <xara@mw-software.com>
Date:
23/06/06
Parameters:
pLastFormattedNode - the most recently fitted node [INPUTS] IsLastTabSection - TRUE if this section has been terminated by EOL or a line break (i.e., not by a Tab), which means we should add ExtraSpaceOnChars/Space here)
Returns:
ptr to char to break at (or NULL if ERROR)

Definition at line 1086 of file nodetxtl.cpp.

01087 {
01088     // first, set the Tab character's width - this is only necessary for non-Left tabs
01089     // (for left tabs we have already set it when encountering the tab)
01090     if (ActiveTabType != LeftTab)
01091     {
01092         // pLastTabVTN can only be undefined for ActiveTabType == LeftTab
01093         ((HorizontalTab*)pLastTabVTN)->SetCharWidth(RemainingSpace);
01094         ((HorizontalTab*)pLastTabVTN)->SetCharAdvance(RemainingSpace);
01095     }
01096     if (!SetCharPositions) return TRUE;
01097 
01098     // full formatting desired
01099     VisibleTextNode* pVTN = pLastTabVTN ? pLastTabVTN : pFirstVTN;
01100     MILLIPOINT Pos = AnchorPos;
01101     do
01102     {
01103         ERROR2IF(pVTN == NULL, FALSE, "FinishTabSection - unexpected end of line");
01104         if (Pos + CharPosOffset != pVTN->GetPosInLine())
01105         {
01106             pVTN->SetPosInLine(Pos + CharPosOffset);
01107             pVTN->FlagNodeAndDescendantsAffectedAndParentsHaveDescendantAffected(); 
01108         }
01109         Pos += pVTN->GetCharAdvance();
01110         
01111         if (IsLastTabSection && IS_A(pVTN,TextChar))
01112             Pos += ExtraOnChars;
01113         if (IsLastTabSection && pVTN->IsASpace())
01114             Pos += ExtraOnSpaces;
01115         if (pVTN == pLastFormattedNode) break;
01116         pVTN = pVTN->FindNextVTNInLine();
01117     } while(1);
01118     return TRUE;
01119 }

BOOL FormatState::IsAvailable (  MILLIPOINT  CharWidth,
BOOL  IsATab,
BOOL  IsADecimalPoint
) 
 

Test whether a char with width CharWidth can be fitted into the current line.

Author:
Martin Wuerthner <xara@mw-software.com>
Date:
23/06/06
Parameters:
CharWidth - the amount to advance by [INPUTS] IsATab - TRUE if the character to be fitted is a tab IsADecimalPoint - TRUE if the currently active tab is a decimal tab and the character to be formatted is its decimal point character

Definition at line 1193 of file nodetxtl.cpp.

01194 {
01195     // If the full CharWidth still fits, then we can return TRUE straight away
01196     // without having to look at the active tab type
01197     if (Width + CharWidth < FitWidth) return TRUE;
01198     // If the above did not succeed there is no hope in the standard case (last
01199     // tab was left tab or the beginning of the line) - the same is true for a
01200     // tab character because it will start a new tab section, so none of its width
01201     // can go to the left of the current formatting position
01202     if (ActiveTabType == LeftTab || IsATab) return FALSE;
01203 
01204     // For other tab types, things are a bit more complicated because half or
01205     // all of the character can go to the left of the tab stop. Rather than
01206     // duplicating all the AdvanceBy code, we simply advance and backtrack.
01207     MILLIPOINT OldWidth = Width;
01208     MILLIPOINT OldRemainingSpace = RemainingSpace;
01209     AdvanceBy(CharWidth, IsADecimalPoint);
01210     MILLIPOINT NewWidth = Width;
01211     Width = OldWidth;
01212     RemainingSpace = OldRemainingSpace;
01213     return NewWidth < FitWidth;
01214 }

Member Data Documentation

MILLIPOINT FormatState::ActiveTabPos
 

Definition at line 213 of file nodetxtl.h.

TxtTabType FormatState::ActiveTabType
 

Definition at line 212 of file nodetxtl.h.

MILLIPOINT FormatState::AnchorPos
 

Definition at line 219 of file nodetxtl.h.

const MILLIPOINT FormatState::CharPosOffset
 

Definition at line 204 of file nodetxtl.h.

WCHAR FormatState::DecimalPointChar
 

Definition at line 227 of file nodetxtl.h.

BOOL FormatState::DecimalPointFound
 

Definition at line 228 of file nodetxtl.h.

const MILLIPOINT FormatState::ExtraOnChars
 

Definition at line 205 of file nodetxtl.h.

const MILLIPOINT FormatState::ExtraOnSpaces
 

Definition at line 206 of file nodetxtl.h.

const MILLIPOINT FormatState::FitWidth
 

Definition at line 202 of file nodetxtl.h.

VisibleTextNode* const FormatState::pFirstVTN
 

Definition at line 203 of file nodetxtl.h.

VisibleTextNode* FormatState::pLastTabVTN
 

Definition at line 214 of file nodetxtl.h.

MILLIPOINT FormatState::RemainingSpace
 

Definition at line 224 of file nodetxtl.h.

const BOOL FormatState::SetCharPositions
 

Definition at line 201 of file nodetxtl.h.

MILLIPOINT FormatState::Width
 

Definition at line 207 of file nodetxtl.h.

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