windows-nt/Source/XPSP1/NT/multimedia/dshow/mfvideo/msmfcnt/ctext.cpp
2020-09-26 16:20:57 +08:00

362 lines
11 KiB
C++

/*************************************************************************/
/* Copyright (C) 1999 Microsoft Corporation */
/* File: ctext.cpp */
/* Description: Implementation of ctext class for drawing text. */
/* Author: phillu */
/* Date: 10/06/99 */
/*************************************************************************/
#include "stdafx.h"
#include "ctext.h"
/*************************************************************************/
/* Function: CText::CText() */
/* Description: Initialize the properties and states. */
/*************************************************************************/
CText::CText()
{
m_fDirty = true;
m_hFont = NULL;
//properties
m_uiFontSize = 10;
m_uiAlignment = TA_CENTER;
m_clrTextColor = GetSysColor(COLOR_WINDOWTEXT);
m_bstrFontFace = L"Arial";
m_bstrFontStyle = L"Normal";
m_fFontStyleFlags = FS_NORMAL;
m_fFixedSizeFont = false;
}
/*************************************************************************/
/* Function: CText::~CText() */
/* Description: Destroy the cached font. */
/*************************************************************************/
CText::~CText()
{
if (m_hFont)
{
::DeleteObject(m_hFont);
m_hFont = NULL;
}
}
/*************************************************************************/
/* Function: Write */
/* Description: Draw text in the specified rectangle. */
/* The font is not created until drawing text for the first time. */
/* Assume the following settings: */
/* - Use Transparent background mode; no change of bg color */
/* - Vertical alignment is always centered */
/*************************************************************************/
HRESULT CText::Write(HDC hdc, const RECT & rc, const WCHAR * pwszText)
{
USES_CONVERSION;
HRESULT hr = S_OK;
const int cBorderMargin = 2; // 2 pixel margin on left or right border
// set drawing attributes, save the old ones
UINT uiOldAlign = ::SetTextAlign(hdc, m_uiAlignment|TA_BOTTOM);
COLORREF crOldTextColor = ::SetTextColor(hdc, m_clrTextColor);
int iOldBkMode = ::SetBkMode(hdc, TRANSPARENT);
// create the required font
if (m_fDirty)
{
hr = RealizeFont(hdc);
}
HFONT hOldFont = NULL;
if (m_hFont)
{
hOldFont = (HFONT) ::SelectObject(hdc, m_hFont);
}
// set position of text based on alignment
TEXTMETRIC tm;
GetTextMetrics(hdc, &tm);
int x = (rc.left + rc.right)/2;
if (m_uiAlignment == TA_LEFT)
{
x = rc.left + cBorderMargin;
}
else if (m_uiAlignment == TA_RIGHT)
{
x = rc.right - cBorderMargin;
}
// text is aligned at the bottom. Adding half of text height makes
// it to position at the center vertically
int y = (rc.top + rc.bottom)/2 + tm.tmHeight/2;
LPCTSTR strTemp = W2CT(pwszText);
int nLength = _tcslen(strTemp);
if (NULL == strTemp)
{
hr = E_POINTER;
}
else
{
::TextOut(hdc, x, y, strTemp, nLength);
}
// restore original font
if (hOldFont)
{
::SelectObject(hdc, hOldFont);
}
::SetTextAlign(hdc, uiOldAlign);
::SetTextColor(hdc, crOldTextColor);
::SetBkMode(hdc, iOldBkMode);
return hr;
}
/*************************************************************************/
/* Function: GetTextWidth */
/* Description: Get the width of text string based on the current font */
/* and settings. */
/*************************************************************************/
HRESULT CText::GetTextWidth(HDC hdc, const WCHAR * pwszText, SIZE *pSize)
{
USES_CONVERSION;
HRESULT hr = S_OK;
const int cBorderMargin = 2; // 2 pixel margin on left or right border
// create the required font
if (m_fDirty)
{
hr = RealizeFont(hdc);
}
HFONT hOldFont = NULL;
if (m_hFont)
{
hOldFont = (HFONT) ::SelectObject(hdc, m_hFont);
}
LPCTSTR strTemp = W2CT(pwszText);
int nLength = _tcslen(strTemp);
if (NULL == strTemp) // guard agaist a NULL pointer
{
hr = E_POINTER;
}
else
{
::GetTextExtentPoint32(hdc, strTemp, nLength, pSize);
pSize->cx += 2*cBorderMargin;
}
if (hOldFont)
{
::SelectObject(hdc, hOldFont);
}
return hr;
}
/*************************************************************************/
/* Function: RealizeFont */
/* Description: create a font based on the current font style, size etc. */
/* Cache the font. */
/*************************************************************************/
HRESULT CText::RealizeFont(HDC hdc)
{
USES_CONVERSION;
HRESULT hr = S_OK;
if( NULL != m_hFont)
{
::DeleteObject(m_hFont);
m_hFont = NULL;
}
// by default, font size changes with system font size which
// depends on the system screen resolution
int nPixelsPerInch = GetDeviceCaps(hdc, LOGPIXELSY);
// if we fixed the font size, we assume always small font (96 pixels per inch)
if (m_fFixedSizeFont)
{
nPixelsPerInch = 96;
}
int nHeight = -MulDiv(m_uiFontSize, nPixelsPerInch, 72);
m_hFont = ::CreateFont(
nHeight, // logical height of font
0, // logical average character width
0, // angle of escapement
0, // base-line orientation angle
(m_fFontStyleFlags&FS_BOLD)?FW_BOLD:FW_NORMAL,// font weight
(m_fFontStyleFlags&FS_ITALIC)?1:0, // italic attribute flag
(m_fFontStyleFlags&FS_UNDERLINE)?1:0, // underline attribute flag
(m_fFontStyleFlags&FS_STRIKEOUT)?1:0, // strikeout attribute flag
DEFAULT_CHARSET, // character set identifier
OUT_DEFAULT_PRECIS, // output precision
CLIP_DEFAULT_PRECIS, // clipping precision
ANTIALIASED_QUALITY, // output quality
DEFAULT_PITCH, // pitch and family
W2T(m_bstrFontFace.m_str) // pointer to typeface name string
);
if( NULL == m_hFont )
{
DWORD dwErr;
dwErr = GetLastError();
hr = HRESULT_FROM_WIN32(dwErr);
}
m_fDirty = false;
return hr;
}
/*************************************************************************/
/* Function: SetFontSize */
/* Description: set the FontSize property, in pt. */
/*************************************************************************/
void CText::SetFontSize(long lSize)
{
if ((UINT)lSize != m_uiFontSize)
{
m_uiFontSize = (UINT)lSize;
m_fDirty = true;
}
}
/*************************************************************************/
/* Function: SetFixedSizeFont */
/* Description: set flag which indicates whether the font size is fixed */
/* or variable with system font. */
/*************************************************************************/
void CText::SetFixedSizeFont(bool fFixed)
{
if (fFixed != m_fFixedSizeFont)
{
m_fFixedSizeFont = fFixed;
m_fDirty = true;
}
}
/*************************************************************************/
/* Function: SetFontFace */
/* Description: set the FontFace property. */
/*************************************************************************/
void CText::SetFontFace(BSTR pwszFontFace)
{
if (_wcsicmp(m_bstrFontFace, pwszFontFace) != 0)
{
m_bstrFontFace = pwszFontFace;
m_fDirty = true;
}
}
/*************************************************************************/
/* Function: SetFontStyle */
/* Description: set the FontStyle property. The style string should */
/* contain either "Normal", or concatenation of one or more strings of: */
/* "Bold", "Italic", "Underline", "Strikeout". Default is "Normal". */
/*************************************************************************/
void CText::SetFontStyle(BSTR pwszFontStyle)
{
BYTE fFontStyleFlags = FS_NORMAL;
//find a match
if( NULL != wcsstr(pwszFontStyle, L"Normal"))
{
fFontStyleFlags = FS_NORMAL;
}
else
{
// Turn on all styles that match
if( NULL != wcsstr(pwszFontStyle, L"Bold"))
{
fFontStyleFlags |= FS_BOLD;
}
if( NULL != wcsstr(pwszFontStyle, L"Italic"))
{
fFontStyleFlags |= FS_ITALIC;
}
if( NULL != wcsstr(pwszFontStyle, L"Underline"))
{
fFontStyleFlags |= FS_UNDERLINE;
}
if( NULL != wcsstr(pwszFontStyle, L"Strikeout"))
{
fFontStyleFlags |= FS_STRIKEOUT;
}
}
if (fFontStyleFlags != m_fFontStyleFlags)
{
m_fFontStyleFlags = fFontStyleFlags;
m_bstrFontStyle = pwszFontStyle;
m_fDirty = true;
}
}
/*************************************************************************/
/* Function: SetFontSize */
/* Description: set the FontSize property, in pt. */
/*************************************************************************/
void CText::SetTextColor(COLORREF clrColor)
{
if (clrColor != m_clrTextColor)
{
m_clrTextColor = clrColor;
}
}
/*************************************************************************/
/* Function: SetTextAlignment */
/* Description: set the TextAlignment property. It controls the */
/* horizontal text alignment. Must be one of "Left", "Center", or */
/* "Right". Default is "Center". */
/*************************************************************************/
void CText::SetTextAlignment(BSTR pwszAlignment)
{
UINT uiAlignment = 0;
//set the text alignment
if (!_wcsicmp(pwszAlignment, L"Right"))
{
uiAlignment = TA_RIGHT;
}
else if (!_wcsicmp(pwszAlignment, L"Center"))
{
uiAlignment = TA_CENTER;
}
else if (!_wcsicmp(pwszAlignment, L"Left"))
{
uiAlignment = TA_LEFT;
}
if (m_uiAlignment != uiAlignment)
{
m_uiAlignment = uiAlignment;
}
}