/// GetTextMargins - checks to see if we have cached information about the current font, /// returns info about it. /// An MRU of Font margins was considered, but seems like overhead. internal static IntNativeMethods.DRAWTEXTPARAMS GetTextMargins(WindowsGraphics wg, WindowsFont font) { // PERF: operate on a local reference rather than party directly on the thread static one. CachedInfo currentCachedInfo = cachedMeasurementDCInfo; if (currentCachedInfo != null && currentCachedInfo.LeftTextMargin > 0 && currentCachedInfo.RightTextMargin > 0 && font == currentCachedInfo.LastUsedFont) { // we have to return clones as DrawTextEx will modify this struct return(new IntNativeMethods.DRAWTEXTPARAMS(currentCachedInfo.LeftTextMargin, currentCachedInfo.RightTextMargin)); } else if (currentCachedInfo == null) { currentCachedInfo = new CachedInfo(); cachedMeasurementDCInfo = currentCachedInfo; } IntNativeMethods.DRAWTEXTPARAMS drawTextParams = wg.GetTextMargins(font); currentCachedInfo.LeftTextMargin = drawTextParams.iLeftMargin; currentCachedInfo.RightTextMargin = drawTextParams.iRightMargin; // returning a copy here to be consistent with the return value from the cache. return(new IntNativeMethods.DRAWTEXTPARAMS(currentCachedInfo.LeftTextMargin, currentCachedInfo.RightTextMargin)); }
public static int DrawTextEx(HandleRef hDC, string text, ref IntNativeMethods.RECT lpRect, int nFormat, [In, Out] IntNativeMethods.DRAWTEXTPARAMS lpDTParams) { int retVal = DrawTextExW(hDC, text, text.Length, ref lpRect, nFormat, lpDTParams); DbgUtil.AssertWin32(retVal != 0, "DrawTextEx(hdc=[0x{0:X8}], text=[{1}], rect=[{2}], flags=[{3}] failed.", hDC.Handle, text, lpRect, nFormat); return(retVal); }
public static extern int DrawTextExA(HandleRef hDC, byte[] lpszString, int byteCount, ref IntNativeMethods.RECT lpRect, int nFormat, [In, Out] IntNativeMethods.DRAWTEXTPARAMS lpDTParams);
/// <devdoc> /// <para> /// The GDI DrawText does not do multiline alignment when IntTextFormatFlags.SingleLine is not set. This /// adjustment is to workaround that limitation. We don't want to duplicate SelectObject calls here, /// so put your Font in the dc before calling this. /// /// AdjustForVerticalAlignment is only used when the text is multiline and it fits inside the bounds passed in. /// In that case we want the horizontal center of the multiline text to be at the horizontal center of the bounds. /// /// If the text is multiline and it does not fit inside the bounds passed in, then return the bounds that were passed in. /// This way we paint the top of the text at the top of the bounds passed in. /// </para> /// </devdoc> public static Rectangle AdjustForVerticalAlignment(HandleRef hdc, string text, Rectangle bounds, IntTextFormatFlags flags, IntNativeMethods.DRAWTEXTPARAMS dtparams) { Debug.Assert(((uint)flags & GdiUnsupportedFlagMask) == 0, "Some custom flags were left over and are not GDI compliant!"); // Ok if any Top (Cannot test IntTextFormatFlags.Top because it is 0), single line text or measuring text. bool isTop = (flags & IntTextFormatFlags.Bottom) == 0 && (flags & IntTextFormatFlags.VerticalCenter) == 0; if (isTop || ((flags & IntTextFormatFlags.SingleLine) != 0) || ((flags & IntTextFormatFlags.CalculateRectangle) != 0)) { return(bounds); } IntNativeMethods.RECT rect = new IntNativeMethods.RECT(bounds); // Get the text bounds. flags |= IntTextFormatFlags.CalculateRectangle; int textHeight = IntUnsafeNativeMethods.DrawTextEx(hdc, text, ref rect, (int)flags, dtparams); // if the text does not fit inside the bounds then return the bounds that were passed in if (textHeight > bounds.Height) { return(bounds); } Rectangle adjustedBounds = bounds; if ((flags & IntTextFormatFlags.VerticalCenter) != 0) // Middle { adjustedBounds.Y = adjustedBounds.Top + adjustedBounds.Height / 2 - textHeight / 2; } else // Bottom. { adjustedBounds.Y = adjustedBounds.Bottom - textHeight; } return(adjustedBounds); }
/// <devdoc> /// Returns the Size in logical units of the given text using the given Font, and according to the formatting flags. /// The proposed size is used to create a bounding rectangle as follows: /// - If there are multiple lines of text, DrawText uses the width of the rectangle pointed to by /// the lpRect parameter and extends the base of the rectangle to bound the last line of text. /// - If the largest word is wider than the rectangle, the width is expanded. /// - If the text is less than the width of the rectangle, the width is reduced. /// - If there is only one line of text, DrawText modifies the right side of the rectangle so that /// it bounds the last character in the line. /// If the font is null, the hdc's current font will be used. /// /// Note for vertical fonts (if ever supported): DrawTextEx uses GetTextExtentPoint32 for measuring the text and this /// function has the following limitation (from MSDN): /// - This function assumes that the text is horizontal, that is, that the escapement is always 0. This is true for both /// the horizontal and vertical measurements of the text. The application must convert it explicitly. /// </devdoc> public Size MeasureText(string text, WindowsFont font, Size proposedSize, IntTextFormatFlags flags) { Debug.Assert(((uint)flags & GdiUnsupportedFlagMask) == 0, "Some custom flags were left over and are not GDI compliant!"); if (string.IsNullOrEmpty(text)) { return(Size.Empty); } // // DrawText returns a rectangle useful for aligning, but not guaranteed to encompass all // pixels (its not a FitBlackBox, if the text is italicized, it will overhang on the right.) // So we need to account for this. // IntNativeMethods.DRAWTEXTPARAMS dtparams = null; #if OPTIMIZED_MEASUREMENTDC // use the cache if we've got it if (MeasurementDCInfo.IsMeasurementDC(this.DeviceContext)) { dtparams = MeasurementDCInfo.GetTextMargins(this, font); } #endif if (dtparams == null) { dtparams = GetTextMargins(font); } // // If Width / Height are < 0, we need to make them larger or DrawText will return // an unbounded measurement when we actually trying to make it very narrow. // int minWidth = 1 + dtparams.iLeftMargin + dtparams.iRightMargin; if (proposedSize.Width <= minWidth) { proposedSize.Width = minWidth; } if (proposedSize.Height <= 0) { proposedSize.Height = 1; } IntNativeMethods.RECT rect = IntNativeMethods.RECT.FromXYWH(0, 0, proposedSize.Width, proposedSize.Height); HandleRef hdc = new HandleRef(null, this.dc.Hdc); if (font != null) { this.dc.SelectFont(font); } // If proposedSize.Height >= MaxSize.Height it is assumed bounds needed. If flags contain SingleLine and // VerticalCenter or Bottom options, DrawTextEx does not bind the rectangle to the actual text height since // it assumes the text is to be vertically aligned; we need to clear the VerticalCenter and Bottom flags to // get the actual text bounds. if (proposedSize.Height >= MaxSize.Height && (flags & IntTextFormatFlags.SingleLine) != 0) { // Clear vertical-alignment flags. flags &= ~(IntTextFormatFlags.Bottom | IntTextFormatFlags.VerticalCenter); } if (proposedSize.Width == MaxSize.Width) { // PERF: No constraining width means no word break. // in this case, we dont care about word wrapping - there should be enough room to fit it all flags &= ~(IntTextFormatFlags.WordBreak); } flags |= IntTextFormatFlags.CalculateRectangle; IntUnsafeNativeMethods.DrawTextEx(hdc, text, ref rect, (int)flags, dtparams); /* No need to restore previous objects into the dc (see comments on top of the class). * * if( hOldFont != IntPtr.Zero ) * { * this.dc.SelectObject(hOldFont); * } */ return(rect.Size); }
/// <devdoc> /// Draws the text in the given bounds, using the given Font, foreColor and backColor, and according to the specified /// TextFormatFlags flags. /// If font is null, the font currently selected in the hdc is used. /// If foreColor and/or backColor are Color.Empty, the hdc current text and/or background color are used. /// </devdoc> public void DrawText(string text, WindowsFont font, Rectangle bounds, Color foreColor, Color backColor, IntTextFormatFlags flags) { if (string.IsNullOrEmpty(text) || foreColor == Color.Transparent) { return; } Debug.Assert(((uint)flags & GdiUnsupportedFlagMask) == 0, "Some custom flags were left over and are not GDI compliant!"); Debug.Assert((flags & IntTextFormatFlags.CalculateRectangle) == 0, "CalculateRectangle flag is set, text won't be drawn"); HandleRef hdc = new HandleRef(this.dc, this.dc.Hdc); // DrawText requires default text alignment. if (this.dc.TextAlignment != DeviceContextTextAlignment.Default) { this.dc.SetTextAlignment(DeviceContextTextAlignment.Default); } // color empty means use the one currently selected in the dc. if (!foreColor.IsEmpty && foreColor != this.dc.TextColor) { this.dc.SetTextColor(foreColor); } if (font != null) { this.dc.SelectFont(font); } DeviceContextBackgroundMode newBackGndMode = (backColor.IsEmpty || backColor == Color.Transparent) ? DeviceContextBackgroundMode.Transparent : DeviceContextBackgroundMode.Opaque; if (this.dc.BackgroundMode != newBackGndMode) { this.dc.SetBackgroundMode(newBackGndMode); } if (newBackGndMode != DeviceContextBackgroundMode.Transparent && backColor != this.dc.BackgroundColor) { this.dc.SetBackgroundColor(backColor); } IntNativeMethods.DRAWTEXTPARAMS dtparams = GetTextMargins(font); bounds = AdjustForVerticalAlignment(hdc, text, bounds, flags, dtparams); // Adjust unbounded rect to avoid overflow since Rectangle ctr does not do param validation. if (bounds.Width == MaxSize.Width) { bounds.Width = bounds.Width - bounds.X; } if (bounds.Height == MaxSize.Height) { bounds.Height = bounds.Height - bounds.Y; } IntNativeMethods.RECT rect = new IntNativeMethods.RECT(bounds); IntUnsafeNativeMethods.DrawTextEx(hdc, text, ref rect, (int)flags, dtparams); /* No need to restore previous objects into the dc (see comments on top of the class). * * if (hOldFont != IntPtr.Zero) * { * IntUnsafeNativeMethods.SelectObject(hdc, new HandleRef( null, hOldFont)); * } * * if( foreColor != textColor ) * { * this.dc.SetTextColor(textColor); * } * * if( backColor != bkColor ) * { * this.dc.SetBackgroundColor(bkColor); * } * * if( bckMode != newMode ) * { * this.dc.SetBackgroundMode(bckMode); * } * * if( align != DeviceContextTextAlignment.Default ) * { * // Default text alignment required by DrewText. * this.dc.SetTextAlignment(align); * } */ }
public static int DrawTextEx(HandleRef hDC, string text, ref IntNativeMethods.RECT lpRect, int nFormat, [In, Out] IntNativeMethods.DRAWTEXTPARAMS lpDTParams) { int retVal; if (Marshal.SystemDefaultCharSize == 1) { // CapRectangleForWin9x(ref lpRect); // we have to do this because if we pass too big of a value (<= 2^31) to win9x // it fails and returns negative values as the rect in which it painted the text lpRect.top = Math.Min(Int16.MaxValue, lpRect.top); lpRect.left = Math.Min(Int16.MaxValue, lpRect.left); lpRect.right = Math.Min(Int16.MaxValue, lpRect.right); lpRect.bottom = Math.Min(Int16.MaxValue, lpRect.bottom); // Convert Unicode string to ANSI. int byteCount = IntUnsafeNativeMethods.WideCharToMultiByte(IntNativeMethods.CP_ACP, 0, text, text.Length, null, 0, IntPtr.Zero, IntPtr.Zero); byte[] textBytes = new byte[byteCount]; IntUnsafeNativeMethods.WideCharToMultiByte(IntNativeMethods.CP_ACP, 0, text, text.Length, textBytes, textBytes.Length, IntPtr.Zero, IntPtr.Zero); // Security: Windows 95/98/Me: This value may not exceed 8192. byteCount = Math.Min(byteCount, IntNativeMethods.MaxTextLengthInWin9x); retVal = DrawTextExA(hDC, textBytes, byteCount, ref lpRect, nFormat, lpDTParams); } else { retVal = DrawTextExW(hDC, text, text.Length, ref lpRect, nFormat, lpDTParams); } DbgUtil.AssertWin32(retVal != 0, "DrawTextEx(hdc=[0x{0:X8}], text=[{1}], rect=[{2}], flags=[{3}] failed.", unchecked ((int)hDC.Handle), text, lpRect, nFormat); return(retVal); }