Fix function wxControlBase::DoEllipsizeSingleLine to really make sure that the ellipsized string takes less pixels than maxFinalWidthPx.

Add comments to explain in more details what the function does and in particular the valid ranges of all internal variables; fix in that regard both the code of both wxELLIPSIZE_START, wxELLIPSIZE_MIDDLE and wxELLIPSIZE_END.
Add more asserts to check the valid ranges and turn a couple of time-expensive checks in level-2 asserts.
Add a test unit for the wxControl::Ellipsize function.
Fix minor details in the docs of wxControl::Ellipsize.
Closes #11567.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63660 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Francesco Montorsi 2010-03-10 13:57:47 +00:00
parent 8ab11e46c0
commit a37da0fa55
13 changed files with 203 additions and 60 deletions

View File

@ -96,6 +96,10 @@ public:
/**
Replaces parts of the @a label string with ellipsis, if needed, so
that it doesn't exceed @a maxWidth.
Note that this functions is guaranteed to always returns a string
whose rendering on the given DC takes less than @a maxWidth pixels
in horizontal.
@param label
The string to ellipsize
@ -103,11 +107,15 @@ public:
The DC used to retrieve the character widths through the
wxDC::GetPartialTextExtents() function.
@param mode
The ellipsization modes. See ::wxEllipsizeMode.
The ellipsization mode. This is the setting which determines
which part of the string should be replaced by the ellipsis.
See ::wxEllipsizeMode enumeration values for more info.
@param maxWidth
The maximum width of the returned string in pixels.
This argument determines how much characters of the string need to
be removed (and replaced by ellipsis).
@param flags
One or more of the ::wxEllipsize
One or more of the ::wxEllipsizeFlags enumeration values combined.
*/
static wxString Ellipsize(const wxString& label, const wxDC& dc,
wxEllipsizeMode mode, int maxWidth,

View File

@ -242,8 +242,8 @@ wxString wxControlBase::DoEllipsizeSingleLine(const wxString& curLine, const wxD
{
wxASSERT_MSG(replacementWidthPx > 0 && marginWidthPx > 0,
"Invalid parameters");
wxASSERT_MSG(!curLine.Contains('\n'),
"Use Ellipsize() instead!");
wxASSERT_LEVEL_2_MSG(!curLine.Contains('\n'),
"Use Ellipsize() instead!");
wxASSERT_MSG( mode != wxELLIPSIZE_NONE, "shouldn't be called at all then" );
@ -261,92 +261,107 @@ wxString wxControlBase::DoEllipsizeSingleLine(const wxString& curLine, const wxD
wxASSERT(charOffsetsPx.GetCount() == len);
// NOTE: charOffsetsPx[n] is the width in pixels of the first n characters (with the last one INCLUDED)
// thus charOffsetsPx[len-1] is the total width of the string
size_t totalWidthPx = charOffsetsPx.Last();
if ( totalWidthPx <= (size_t)maxFinalWidthPx )
return curLine; // we don't need to do any ellipsization!
int excessPx = totalWidthPx - maxFinalWidthPx +
replacementWidthPx +
marginWidthPx; // security margin (NEEDED!)
wxASSERT(excessPx>0);
int excessPx = wxMin(totalWidthPx - maxFinalWidthPx +
replacementWidthPx +
marginWidthPx, // security margin
totalWidthPx);
wxASSERT(excessPx>0); // excessPx should be in the [1;totalWidthPx] range
// remove characters in excess
size_t initialCharToRemove, // index of first char to erase
nCharsToRemove; // how many chars do we need to erase?
// REMEMBER: indexes inside the string have a valid range of [0;len-1] if not otherwise constrained
// lengths/counts of characters (e.g. nCharsToRemove) have a valid range of [0;len] if not otherwise constrained
// NOTE: since this point we know we have for sure a non-empty string from which we need
// to remove _at least_ one character (thus nCharsToRemove below is constrained to be >= 1)
size_t initialCharToRemove, // index of first character to erase, valid range is [0;len-1]
nCharsToRemove; // how many chars do we need to erase? valid range is [1;len-initialCharToRemove]
// let's compute the range of characters to remove depending on the ellipsization mode:
switch (mode)
{
case wxELLIPSIZE_START:
initialCharToRemove = 0;
for ( nCharsToRemove=0;
nCharsToRemove < len && charOffsetsPx[nCharsToRemove] < excessPx;
for ( nCharsToRemove = 1;
nCharsToRemove < len && charOffsetsPx[nCharsToRemove-1] < excessPx;
nCharsToRemove++ )
;
break;
case wxELLIPSIZE_MIDDLE:
{
// the start & end of the removed span of chars
// NOTE: the following piece of code works also when len == 1
// start the removal process from the middle of the string
// i.e. separe the string in three parts:
// - the first one to preserve, valid range [0;initialCharToRemove-1] or the empty range if initialCharToRemove==0
// - the second one to remove, valid range [initialCharToRemove;endCharToRemove]
// - the third one to preserve, valid range [endCharToRemove+1;len-1] or the empty range if endCharToRemove==len-1
// NOTE: empty range != range [0;0] since the range [0;0] contains 1 character (the zero-th one)!
initialCharToRemove = len/2;
size_t endChar = len/2;
size_t endCharToRemove = len/2; // index of the last character to remove; valid range is [0;len-1]
int removedPx = 0;
for ( ; removedPx < excessPx; )
{
// try to remove the last character of the first part of the string
if (initialCharToRemove > 0)
{
// widthPx of the initialCharToRemove-th character
int widthPx = charOffsetsPx[initialCharToRemove] -
charOffsetsPx[initialCharToRemove-1];
// width of the (initialCharToRemove-1)-th character
int widthPx;
if (initialCharToRemove >= 2)
widthPx = charOffsetsPx[initialCharToRemove-1] - charOffsetsPx[initialCharToRemove-2];
else
widthPx = charOffsetsPx[initialCharToRemove-1];
// the (initialCharToRemove-1)-th character is the first char of the string
wxASSERT(widthPx >= 0); // widthPx is zero for e.g. tab characters
// remove the initialCharToRemove-th character
removedPx += widthPx;
// mark the (initialCharToRemove-1)-th character as removable
initialCharToRemove--;
removedPx += widthPx;
}
if (endChar < len - 1 &&
// try to remove the first character of the last part of the string
if (endCharToRemove < len - 1 &&
removedPx < excessPx)
{
// widthPx of the (endChar+1)-th character
int widthPx = charOffsetsPx[endChar+1] -
charOffsetsPx[endChar];
// width of the (endCharToRemove+1)-th character
int widthPx = charOffsetsPx[endCharToRemove+1] -
charOffsetsPx[endCharToRemove];
// remove the endChar-th character
wxASSERT(widthPx >= 0); // widthPx is zero for e.g. tab characters
// mark the (endCharToRemove+1)-th character as removable
endCharToRemove++;
removedPx += widthPx;
endChar++;
}
if (initialCharToRemove == 0 && endChar == len-1)
if (initialCharToRemove == 0 && endCharToRemove == len-1)
{
nCharsToRemove = len+1;
// we need to remove all the characters of the string!
break;
}
}
initialCharToRemove++;
nCharsToRemove = endChar - initialCharToRemove + 1;
nCharsToRemove = endCharToRemove - initialCharToRemove + 1;
}
break;
case wxELLIPSIZE_END:
{
wxASSERT(len > 0);
int maxWidthPx = totalWidthPx - excessPx;
for ( initialCharToRemove = 0;
initialCharToRemove < len && charOffsetsPx[initialCharToRemove] < maxWidthPx;
initialCharToRemove++ )
;
if (initialCharToRemove == 0)
{
nCharsToRemove = len;
}
else
{
//initialCharToRemove--; // go back one character
nCharsToRemove = len - initialCharToRemove;
}
// go backward from the end of the string toward the start
for ( initialCharToRemove = len-1;
initialCharToRemove > 0 && charOffsetsPx[initialCharToRemove-1] > maxWidthPx;
initialCharToRemove-- )
;
nCharsToRemove = len - initialCharToRemove;
}
break;
@ -356,25 +371,31 @@ wxString wxControlBase::DoEllipsizeSingleLine(const wxString& curLine, const wxD
return curLine;
}
wxString ret(curLine);
if (nCharsToRemove >= len)
{
// need to remove the entire row!
ret.clear();
}
else
{
// erase nCharsToRemove characters after initialCharToRemove (included):
ret.erase(initialCharToRemove, nCharsToRemove+1);
wxASSERT(initialCharToRemove >= 0 && initialCharToRemove <= len-1); // see valid range for initialCharToRemove above
wxASSERT(nCharsToRemove >= 1 && nCharsToRemove <= len-initialCharToRemove); // see valid range for nCharsToRemove above
// if there is space for the replacement dots, add them
if (maxFinalWidthPx > replacementWidthPx)
ret.insert(initialCharToRemove, wxELLIPSE_REPLACEMENT);
}
// erase nCharsToRemove characters after initialCharToRemove (included);
// e.g. if we have the string "foobar" (len = 6)
// ^
// \--- initialCharToRemove = 2
// and nCharsToRemove = 2, then we get "foar"
wxString ret(curLine);
ret.erase(initialCharToRemove, nCharsToRemove);
int removedPx;
if (initialCharToRemove >= 1)
removedPx = charOffsetsPx[initialCharToRemove+nCharsToRemove-1] - charOffsetsPx[initialCharToRemove-1];
else
removedPx = charOffsetsPx[initialCharToRemove+nCharsToRemove-1];
wxASSERT(removedPx >= excessPx);
// if there is space for the replacement dots, add them
if ((int)totalWidthPx-removedPx+replacementWidthPx < maxFinalWidthPx)
ret.insert(initialCharToRemove, wxELLIPSE_REPLACEMENT);
// if everything was ok, we should have shortened this line
// enough to make it fit in maxFinalWidthPx:
wxASSERT(dc.GetTextExtent(ret).GetWidth() < maxFinalWidthPx);
wxASSERT_LEVEL_2(dc.GetTextExtent(ret).GetWidth() <= maxFinalWidthPx);
return ret;
}

View File

@ -136,6 +136,7 @@ TEST_GUI_OBJECTS = \
test_gui_size.o \
test_gui_point.o \
test_gui_colour.o \
test_gui_ellipsization.o \
test_gui_measuring.o \
test_gui_config.o \
test_gui_comboboxtest.o \
@ -573,6 +574,9 @@ test_gui_point.o: $(srcdir)/geometry/point.cpp $(TEST_GUI_ODEP)
test_gui_colour.o: $(srcdir)/graphics/colour.cpp $(TEST_GUI_ODEP)
$(CXXC) -c -o $@ $(TEST_GUI_CXXFLAGS) $(srcdir)/graphics/colour.cpp
test_gui_ellipsization.o: $(srcdir)/graphics/ellipsization.cpp $(TEST_GUI_ODEP)
$(CXXC) -c -o $@ $(TEST_GUI_CXXFLAGS) $(srcdir)/graphics/ellipsization.cpp
test_gui_measuring.o: $(srcdir)/graphics/measuring.cpp $(TEST_GUI_ODEP)
$(CXXC) -c -o $@ $(TEST_GUI_CXXFLAGS) $(srcdir)/graphics/measuring.cpp

View File

@ -0,0 +1,78 @@
///////////////////////////////////////////////////////////////////////////////
// Name: tests/graphics/ellipsization.cpp
// Purpose: wxControlBase::*Ellipsize* unit test
// Author: Francesco Montorsi
// Created: 2010-03-10
// RCS-ID: $Id$
// Copyright: (c) 2010 Francesco Montorsi
///////////////////////////////////////////////////////////////////////////////
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
#include "testprec.h"
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#include "wx/control.h"
#include "wx/dcmemory.h"
// ----------------------------------------------------------------------------
// test class
// ----------------------------------------------------------------------------
class EllipsizationTestCase : public CppUnit::TestCase
{
public:
EllipsizationTestCase() { }
private:
CPPUNIT_TEST_SUITE( EllipsizationTestCase );
CPPUNIT_TEST( Ellipsize );
CPPUNIT_TEST_SUITE_END();
void Ellipsize();
DECLARE_NO_COPY_CLASS(EllipsizationTestCase)
};
// register in the unnamed registry so that these tests are run by default
CPPUNIT_TEST_SUITE_REGISTRATION( EllipsizationTestCase );
// also include in it's own registry so that these tests can be run alone
CPPUNIT_TEST_SUITE_NAMED_REGISTRATION( EllipsizationTestCase, "EllipsizationTestCase" );
void EllipsizationTestCase::Ellipsize()
{
wxMemoryDC dc;
wxString stringsToTest[] =
{
"N", ".", "x", "foobar", wxS("\u03B1"), "Another test", "a very very very very very very very long string",
"\xCE\xB1\xCE\xB2\xCE\xB3\xCE\xB4\xCE\xB5\xCE\xB6\xCE\xB7\xCE\xB8\xCE\xB9",
// alpha+beta+gamma+delta+epsilon+zeta+eta+theta+iota
"\t", "\t\t\t\t\t", "a\tstring\twith\ttabs",
"\n", "\n\n\n\n\n", "a\nstring\nwith\nnewlines",
"&", "&&&&&&&", "a&string&with&newlines",
"\t\n&", "a\t\n&string\t\n&with\t\n&many\t\n&chars"
};
int flagsToTest[] = { 0, wxELLIPSIZE_FLAGS_PROCESS_MNEMONICS, wxELLIPSIZE_FLAGS_EXPAND_TABS,
wxELLIPSIZE_FLAGS_PROCESS_MNEMONICS|wxELLIPSIZE_FLAGS_EXPAND_TABS };
wxEllipsizeMode modesToTest[] = { wxELLIPSIZE_START, wxELLIPSIZE_MIDDLE, wxELLIPSIZE_END };
int widthsToTest[] = { 0, 1, 2, 3, 10, 20, 100 };
for (unsigned int s=0; s<WXSIZEOF(stringsToTest); s++)
for (unsigned int f=0; f<WXSIZEOF(flagsToTest); f++)
for (unsigned int m=0; m<WXSIZEOF(modesToTest); m++)
for (unsigned int w=0; w<WXSIZEOF(widthsToTest); w++)
{
wxString ret = wxControlBase::Ellipsize(stringsToTest[s], dc, modesToTest[m],
widthsToTest[w], flagsToTest[f]);
CPPUNIT_ASSERT_MESSAGE((std::string)("invalid ellipsization for: " + stringsToTest[s]),
dc.GetMultiLineTextExtent(ret).GetWidth() <= widthsToTest[w]);
}
}

View File

@ -121,6 +121,7 @@ TEST_GUI_OBJECTS = \
$(OBJS)\test_gui_size.obj \
$(OBJS)\test_gui_point.obj \
$(OBJS)\test_gui_colour.obj \
$(OBJS)\test_gui_ellipsization.obj \
$(OBJS)\test_gui_measuring.obj \
$(OBJS)\test_gui_config.obj \
$(OBJS)\test_gui_comboboxtest.obj \
@ -627,6 +628,9 @@ $(OBJS)\test_gui_point.obj: .\geometry\point.cpp
$(OBJS)\test_gui_colour.obj: .\graphics\colour.cpp
$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\graphics\colour.cpp
$(OBJS)\test_gui_ellipsization.obj: .\graphics\ellipsization.cpp
$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\graphics\ellipsization.cpp
$(OBJS)\test_gui_measuring.obj: .\graphics\measuring.cpp
$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\graphics\measuring.cpp

View File

@ -115,6 +115,7 @@ TEST_GUI_OBJECTS = \
$(OBJS)\test_gui_size.o \
$(OBJS)\test_gui_point.o \
$(OBJS)\test_gui_colour.o \
$(OBJS)\test_gui_ellipsization.o \
$(OBJS)\test_gui_measuring.o \
$(OBJS)\test_gui_config.o \
$(OBJS)\test_gui_comboboxtest.o \
@ -609,6 +610,9 @@ $(OBJS)\test_gui_point.o: ./geometry/point.cpp
$(OBJS)\test_gui_colour.o: ./graphics/colour.cpp
$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
$(OBJS)\test_gui_ellipsization.o: ./graphics/ellipsization.cpp
$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
$(OBJS)\test_gui_measuring.o: ./graphics/measuring.cpp
$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<

View File

@ -116,6 +116,7 @@ TEST_GUI_OBJECTS = \
$(OBJS)\test_gui_size.obj \
$(OBJS)\test_gui_point.obj \
$(OBJS)\test_gui_colour.obj \
$(OBJS)\test_gui_ellipsization.obj \
$(OBJS)\test_gui_measuring.obj \
$(OBJS)\test_gui_config.obj \
$(OBJS)\test_gui_comboboxtest.obj \
@ -753,6 +754,9 @@ $(OBJS)\test_gui_point.obj: .\geometry\point.cpp
$(OBJS)\test_gui_colour.obj: .\graphics\colour.cpp
$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\graphics\colour.cpp
$(OBJS)\test_gui_ellipsization.obj: .\graphics\ellipsization.cpp
$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\graphics\ellipsization.cpp
$(OBJS)\test_gui_measuring.obj: .\graphics\measuring.cpp
$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\graphics\measuring.cpp

View File

@ -359,6 +359,7 @@ TEST_GUI_OBJECTS = &
$(OBJS)\test_gui_size.obj &
$(OBJS)\test_gui_point.obj &
$(OBJS)\test_gui_colour.obj &
$(OBJS)\test_gui_ellipsization.obj &
$(OBJS)\test_gui_measuring.obj &
$(OBJS)\test_gui_config.obj &
$(OBJS)\test_gui_comboboxtest.obj &
@ -664,6 +665,9 @@ $(OBJS)\test_gui_point.obj : .AUTODEPEND .\geometry\point.cpp
$(OBJS)\test_gui_colour.obj : .AUTODEPEND .\graphics\colour.cpp
$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
$(OBJS)\test_gui_ellipsization.obj : .AUTODEPEND .\graphics\ellipsization.cpp
$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
$(OBJS)\test_gui_measuring.obj : .AUTODEPEND .\graphics\measuring.cpp
$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<

View File

@ -117,6 +117,7 @@
geometry/size.cpp
geometry/point.cpp
graphics/colour.cpp
graphics/ellipsization.cpp
graphics/measuring.cpp
config/config.cpp
controls/comboboxtest.cpp

View File

@ -261,6 +261,10 @@ SOURCE=.\dummy.cpp
# End Source File
# Begin Source File
SOURCE=.\graphics\ellipsization.cpp
# End Source File
# Begin Source File
SOURCE=.\font\fonttest.cpp
# End Source File
# Begin Source File

View File

@ -631,6 +631,9 @@
UsePrecompiledHeader="1"/>
</FileConfiguration>
</File>
<File
RelativePath=".\graphics\ellipsization.cpp">
</File>
<File
RelativePath=".\font\fonttest.cpp">
</File>

View File

@ -915,6 +915,10 @@
/>
</FileConfiguration>
</File>
<File
RelativePath=".\graphics\ellipsization.cpp"
>
</File>
<File
RelativePath=".\font\fonttest.cpp"
>

View File

@ -887,6 +887,10 @@
/>
</FileConfiguration>
</File>
<File
RelativePath=".\graphics\ellipsization.cpp"
>
</File>
<File
RelativePath=".\font\fonttest.cpp"
>