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Diffstat (limited to 'source/ShiftUI/Internal/TextBoxTextRenderer.cs')
| -rw-r--r-- | source/ShiftUI/Internal/TextBoxTextRenderer.cs | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/source/ShiftUI/Internal/TextBoxTextRenderer.cs b/source/ShiftUI/Internal/TextBoxTextRenderer.cs new file mode 100644 index 0000000..3e908f3 --- /dev/null +++ b/source/ShiftUI/Internal/TextBoxTextRenderer.cs @@ -0,0 +1,131 @@ +// Permission is hereby granted, free of charge, to any person obtaining +// a copy of this software and associated documentation files (the +// "Software"), to deal in the Software without restriction, including +// without limitation the rights to use, copy, modify, merge, publish, +// distribute, sublicense, and/or sell copies of the Software, and to +// permit persons to whom the Software is furnished to do so, subject to +// the following conditions: +// +// The above copyright notice and this permission notice shall be +// included in all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +// +// Copyright (c) 2007 Novell, Inc. (http://www.novell.com) +// +// Authors: +// Jonathan Pobst [email protected] +// +// + +using System; +using System.Drawing; +using System.Drawing.Text; +using System.Text; +using System.Collections; + +namespace ShiftUI +{ + internal class TextBoxTextRenderer + { + private static Size max_size; + private static bool use_textrenderer; + private static StringFormat sf_nonprinting; + private static StringFormat sf_printing; + private static Hashtable measure_cache; + + static TextBoxTextRenderer () + { + // On Windows, we want to use TextRenderer (GDI) + // On Linux, we want to use DrawString (GDI+) + // TextRenderer provides translation from TextRenderer to + // DrawString, but I doubt it's exact enough. + // Another option would be to put Pango here for Linux. + int platform = (int)Environment.OSVersion.Platform; + + if (platform == 4 || platform == 128 || platform == 6) + use_textrenderer = false; + else + use_textrenderer = true; + + // windows 2000 doesn't draw with gdi if bounds are In32.MaxValue + max_size = new Size (Int16.MaxValue, Int16.MaxValue); + + sf_nonprinting = new StringFormat (StringFormat.GenericTypographic); + sf_nonprinting.Trimming = StringTrimming.None; + sf_nonprinting.FormatFlags = StringFormatFlags.DisplayFormatControl; + sf_nonprinting.HotkeyPrefix = HotkeyPrefix.None; + + sf_printing = StringFormat.GenericTypographic; + sf_printing.HotkeyPrefix = HotkeyPrefix.None; + + measure_cache = new Hashtable (); + } + + public static void DrawText (Graphics g, string text, Font font, Color color, float x, float y, bool showNonPrint) + { + if (!use_textrenderer) { + if (showNonPrint) + g.DrawString (text, font, ThemeEngine.Current.ResPool.GetSolidBrush (color), x, y, sf_nonprinting); + else + g.DrawString (text, font, ThemeEngine.Current.ResPool.GetSolidBrush (color), x, y, sf_printing); + } else { + if (showNonPrint) + TextRenderer.DrawTextInternal (g, text, font, new Rectangle (new Point ((int)x, (int)y), max_size), color, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false); + else + TextRenderer.DrawTextInternal (g, text, font, new Rectangle (new Point ((int)x, (int)y), max_size), color, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false); + } + } + + public static SizeF MeasureText (Graphics g, string text, Font font) + { + // Due to the way the TextBox currently works, it measures each + // character one at a time. And it does this alot. So here we + // are implementing a cache for each font/character combination + // measurement. Since the number of fonts and number of characters + // used tends to be small, this is a good performance gain for + // not too much memory. + if (text.Length == 1) { + // If g.VisibleClipBounds is {X=0, Y=0, Width=1, Height=1}, then some characters + // (in some fonts for some point sizes) return a different width then when the + // VisibleClipBounds has a different (usually but not always more reasonable) value. + // This state of the Graphics object can occur during initialization of text boxes + // with preset Text values. See https://bugzilla.xamarin.com/show_bug.cgi?id=26258 + // for more details. + string sep; + var bounds = g.VisibleClipBounds; + if (bounds.Width == 1 && bounds.Height == 1 && bounds.X == 0 && bounds.Y == 0) + sep = "-1x1|"; + else + sep = "|"; + string key = font.GetHashCode ().ToString () + sep + text; + + if (measure_cache.ContainsKey (key)) { + return (SizeF)measure_cache[key]; + } else { + SizeF size; + + if (!use_textrenderer) + size = g.MeasureString (text, font, 10000, sf_nonprinting); + else + size = TextRenderer.MeasureTextInternal (g, text, font, Size.Empty, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false); + + measure_cache[key] = size; + + return size; + } + } + + if (!use_textrenderer) + return g.MeasureString (text, font, 10000, sf_nonprinting); + else + return TextRenderer.MeasureTextInternal (g, text, font, Size.Empty, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false); + } + } +} |