/// <summary> /// Measure the width of string under max width restriction calculating the number of characters that can fit and the width those characters take.<br/> /// </summary> /// <param name="str">the string to measure</param> /// <param name="font">the font to measure string with</param> /// <param name="maxWidth">the max width to calculate fit characters</param> /// <param name="charFit">the number of characters that will fit under <see cref="maxWidth"/> restriction</param> /// <param name="charFitWidth">the width that only the characters that fit into max width take</param> public abstract void MeasureString(string str, RFont font, double maxWidth, out int charFit, out double charFitWidth);
/// <summary> /// Measure the width and height of string <paramref name="str"/> when drawn on device context HDC /// using the given font <paramref name="font"/>. /// </summary> /// <param name="str">the string to measure</param> /// <param name="font">the font to measure string with</param> /// <returns>the size of the string</returns> public abstract RSize MeasureString(string str, RFont font);
/// <summary> /// Draw the given string using the given font and foreground color at given location. /// </summary> /// <param name="str">the string to draw</param> /// <param name="font">the font to use to draw the string</param> /// <param name="color">the text color to set</param> /// <param name="point">the location to start string draw (top-left)</param> /// <param name="size">used to know the size of the rendered text for transparent text support</param> /// <param name="rtl">is to render the string right-to-left (true - RTL, false - LTR)</param> public abstract void DrawString(String str, RFont font, RColor color, RPoint point, RSize size, bool rtl);
/// <summary> /// Measure the width and height of string <paramref name="str"/> when drawn on device context HDC /// using the given font <paramref name="font"/>. /// </summary> /// <param name="str">the string to measure</param> /// <param name="font">the font to measure string with</param> /// <returns>the size of the string</returns> public abstract RSize MeasureString(string str, RFont font);
/// <summary> /// Measure the width of string under max width restriction calculating the number of characters that can fit and the width those characters take.<br/> /// Not relevant for platforms that don't render HTML on UI element. /// </summary> /// <param name="str">the string to measure</param> /// <param name="font">the font to measure string with</param> /// <param name="maxWidth">the max width to calculate fit characters</param> /// <param name="charFit">the number of characters that will fit under <see cref="maxWidth"/> restriction</param> /// <param name="charFitWidth">the width that only the characters that fit into max width take</param> public abstract void MeasureString(string str, RFont font, double maxWidth, out int charFit, out double charFitWidth);
/// <summary>
/// Set a resource (e.g. a font) for the specified device context.
/// WARNING: Calling Font.ToHfont() many times without releasing the font handle crashes the app.
/// </summary>
private void SetFont(RFont font)
{
InitHdc();
Win32Utils.SelectObject(_hdc, ((FontAdapter)font).HFont);
}
/// <summary> /// Draw the given string using the given font and foreground color at given location. /// </summary> /// <param name="str">the string to draw</param> /// <param name="font">the font to use to draw the string</param> /// <param name="color">the text color to set</param> /// <param name="point">the location to start string draw (top-left)</param> /// <param name="size">used to know the size of the rendered text for transparent text support</param> /// <param name="rtl">is to render the string right-to-left (true - RTL, false - LTR)</param> public abstract void DrawString(String str, RFont font, RColor color, RPoint point, RSize size, bool rtl);
/// <summary>
/// Special draw logic to draw transparent text using GDI.<br/>
/// 1. Create in-memory DC<br/>
/// 2. Copy background to in-memory DC<br/>
/// 3. Draw the text to in-memory DC<br/>
/// 4. Copy the in-memory DC to the proper location with alpha blend<br/>
/// </summary>
private static void DrawTransparentText(IntPtr hdc, string str, RFont font, Point point, Size size, Color color)
{
IntPtr dib;
var memoryHdc = Win32Utils.CreateMemoryHdc(hdc, size.Width, size.Height, out dib);
try
{
// copy target background to memory HDC so when copied back it will have the proper background
Win32Utils.BitBlt(memoryHdc, 0, 0, size.Width, size.Height, hdc, point.X, point.Y, Win32Utils.BitBltCopy);
// Create and select font
Win32Utils.SelectObject(memoryHdc, ((FontAdapter)font).HFont);
Win32Utils.SetTextColor(memoryHdc, (color.B & 0xFF) << 16 | (color.G & 0xFF) << 8 | color.R);
// Draw text to memory HDC
Win32Utils.TextOut(memoryHdc, 0, 0, str, str.Length);
// copy from memory HDC to normal HDC with alpha blend so achieve the transparent text
Win32Utils.AlphaBlend(hdc, point.X, point.Y, size.Width, size.Height, memoryHdc, 0, 0, size.Width, size.Height, new BlendFunction(color.A));
}
finally
{
Win32Utils.ReleaseMemoryHdc(memoryHdc, dib);
}
}
public override void MeasureString(string str, RFont font, double maxWidth, out int charFit, out double charFitWidth)
{
charFit = 0;
charFitWidth = 0;
if (_useGdiPlusTextRendering)
{
ReleaseHdc();
var size = MeasureString(str, font);
for (int i = 1; i <= str.Length; i++)
{
charFit = i - 1;
RSize pSize = MeasureString(str.Substring(0, i), font);
if (pSize.Height <= size.Height && pSize.Width < maxWidth)
charFitWidth = pSize.Width;
else
break;
}
}
else
{
#if !MONO
SetFont(font);
var size = new Size();
Win32Utils.GetTextExtentExPoint(_hdc, str, str.Length, (int)Math.Round(maxWidth), _charFit, _charFitWidth, ref size);
charFit = _charFit[0];
charFitWidth = charFit > 0 ? _charFitWidth[charFit - 1] : 0;
#endif
}
}
public override RSize MeasureString(string str, RFont font)
{
if (_useGdiPlusTextRendering)
{
ReleaseHdc();
var fontAdapter = (FontAdapter)font;
var realFont = fontAdapter.Font;
_characterRanges[0] = new CharacterRange(0, str.Length);
_stringFormat.SetMeasurableCharacterRanges(_characterRanges);
var size = _g.MeasureCharacterRanges(str, realFont, RectangleF.Empty, _stringFormat)[0].GetBounds(_g).Size;
if (font.Height < 0)
{
var height = realFont.Height;
var descent = realFont.Size * realFont.FontFamily.GetCellDescent(realFont.Style) / realFont.FontFamily.GetEmHeight(realFont.Style);
fontAdapter.SetMetrics(height, (int)Math.Round((height - descent + .5f)));
}
return Utils.Convert(size);
}
else
{
#if !MONO
SetFont(font);
var size = new Size();
Win32Utils.GetTextExtentPoint32(_hdc, str, str.Length, ref size);
if (font.Height < 0)
{
TextMetric lptm;
Win32Utils.GetTextMetrics(_hdc, out lptm);
((FontAdapter)font).SetMetrics(size.Height, lptm.tmHeight - lptm.tmDescent + lptm.tmUnderlined + 1);
}
return Utils.Convert(size);
#else
throw new InvalidProgramException("Invalid Mono code");
#endif
}
}
public override void DrawString(string str, RFont font, RColor color, RPoint point, RSize size, bool rtl)
{
if (_useGdiPlusTextRendering)
{
ReleaseHdc();
SetRtlAlignGdiPlus(rtl);
var brush = ((BrushAdapter)_adapter.GetSolidBrush(color)).Brush;
_g.DrawString(str, ((FontAdapter)font).Font, brush, (int)(Math.Round(point.X) + (rtl ? size.Width : 0)), (int)Math.Round(point.Y), _stringFormat2);
}
else
{
#if !MONO
var pointConv = Utils.ConvertRound(point);
var colorConv = Utils.Convert(color);
if (color.A == 255)
{
SetFont(font);
SetTextColor(colorConv);
SetRtlAlignGdi(rtl);
Win32Utils.TextOut(_hdc, pointConv.X, pointConv.Y, str, str.Length);
}
else
{
InitHdc();
SetRtlAlignGdi(rtl);
DrawTransparentText(_hdc, str, font, pointConv, Utils.ConvertRound(size), colorConv);
}
#endif
}
}
public override void MeasureString(string str, RFont font, double maxWidth, out int charFit, out double charFitWidth)
{
using (var g = new GraphicsAdapter(_control.CreateGraphics(), _useGdiPlusTextRendering, true))
{
g.MeasureString(str, font, maxWidth, out charFit, out charFitWidth);
}
}