During the last week I had to make a custom control that should have had a richTextBox control with a toolbar that contains: a dropdown of fonts and one with font sizes plus 3 buttons(which in fact are checkboxes with Appearance of a button) that will emulate 'make bold', 'make italic', 'make underline'. Of course there could be other improvements but client was happy with only these controls.
I will try to explain you which are the steps in the next lines:
- create a new control - ExtraRichTextBoxUC
- add 2 comboboxes with drop down style set on DropDownList: cmbFontFamily, cmbFontSize
- add 3 checkBoxes with Appearance on Button: ckbBold, ckbItalic, ckbUnderline
- finally you add a richTextBox control: txtFunctionality
Generate event methods for controls as follows: cmbFontFamily_SelectedIndexChanged, cmbFontSize_SelectedIndexChanged, ckbBold_CheckedChanged, ckbItalic_CheckedChanged, ckbUnderline_CheckedChanged.
I think that one of the most important methods from bellow is
ChangeFontStyleForSelectedText. You have to understand that when you want to change font for a text you must iterate character by character and change font. First I thought that a style can be applied a word or a phrase. To issue is that styles are overwritten in such a case so you must iterate each letter.
So for each text that you want to change font you copy in a memory RichTextBox(so you won't cause flickering on current richTextBox) and set new font. Finally that rtf generated you assign to current richTextBox.
private void ChangeFontStyleForSelectedText(string familyName, float? emSize, FontStyle? fontStyle, bool? enableFontStyle)
{
_maskChanges = true;
try
{
int txtStartPosition = txtFunctionality.SelectionStart;
int selectionLength = txtFunctionality.SelectionLength;
if (selectionLength > 0)
using (RichTextBox txtTemp = new RichTextBox())
{
txtTemp.Rtf = txtFunctionality.SelectedRtf;
for (int i = 0; i < selectionLength; ++i)
{
txtTemp.Select(i, 1);
txtTemp.SelectionFont = RenderFont(txtTemp.SelectionFont, familyName, emSize, fontStyle, enableFontStyle);
}
txtTemp.Select(0, selectionLength);
txtFunctionality.SelectedRtf = txtTemp.SelectedRtf;
txtFunctionality.Select(txtStartPosition, selectionLength);
}
}
finally
{
_maskChanges = false;
}
}
Next method important that I had to work a little on is
RenderFont:
///
/// Changes a font from originalFont appending other properties
///
/// Original font of text
/// Target family name
/// Target text Size
/// Target font style
/// true when enable false when disable
/// A new font with all provided properties added/removed to original font
private Font RenderFont(Font originalFont, string familyName, float? emSize, FontStyle? fontStyle, bool? enableFontStyle)
{
if (fontStyle.HasValue && fontStyle != FontStyle.Regular && fontStyle != FontStyle.Bold && fontStyle != FontStyle.Italic && fontStyle != FontStyle.Underline)
throw new System.InvalidProgramException("Invalid style parameter to ChangeFontStyleForSelectedText");
Font newFont;
FontStyle? newStyle = null;
if (fontStyle.HasValue)
{
if (fontStyle.HasValue && fontStyle == FontStyle.Regular)
newStyle = fontStyle.Value;
else if (originalFont != null && enableFontStyle.HasValue && enableFontStyle.Value)
newStyle = originalFont.Style | fontStyle.Value;
else
newStyle = originalFont.Style & ~fontStyle.Value;
}
newFont = new Font(!string.IsNullOrEmpty(familyName) ? familyName : originalFont.FontFamily.Name,
emSize.HasValue ? emSize.Value : originalFont.Size,
newStyle.HasValue ? newStyle.Value : originalFont.Style);
return newFont;
}
Observation: you must highlight the toolbar for your current position. For that after you load the rtf text you must position on first position of your text and according to that font you show font family, font size, if is bold - underline or italic.
In order to catch key combination of Ctrl+B, Ctrl+I, Ctrl+U you will use _KeyDown event of richTextBox control. For Control+I you must use a trick. Setting SuppressKeyPress = true will avoid executing 'Insert TAB' :)
In order to avoid flickering of text in richTextBox control especially when you delete last letter of control or when you try to detect font for first letter of textBox you have to use another trick. Use Suspend/Resume methods of next extension.
namespace System.Windows.Forms
{
public static class ControlExtensions
{
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern bool LockWindowUpdate(IntPtr hWndLock);
//Method used agains flickering
public static void Suspend(this Control control)
{
LockWindowUpdate(control.Handle);
}
public static void Resume(this Control control)
{
LockWindowUpdate(IntPtr.Zero);
}
}
}
I hope that this will help you a lot. When I searched around I did not found such as a control that will make a simple richTextBox with simple toolbar controls. If you encounter issues implementing it feel free to ask. I could also share code but I don't know a good reliable service to share files and not to be removed after a while :-? Do you?
Full code of control:
public partial class ExtraRichTextBoxUC : UserControl
{
private bool _maskChanges;
public ExtraRichTextBoxUC()
{
InitializeComponent();
LoadData();
DisplayData();
}
private void DisplayData()
{
//dummy data to preview
txtFunctionality.Rtf = @"{\rtf1\ansi\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fnil\fcharset0 Tahoma;}{\f1\fnil\fcharset0 Times New Roman;}}\viewkind4\uc1\pard\b\f0\fs18 W\b0 indows 8.1, Windows Server 2012 R2, \b Windows\b0 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 \fs24 R2 (Server \fs18 Core Role \ul supported with SP1 \ulnone or later; Itanium \fs24 not supported\fs18 ).NET Framework does not support all versions of \fs26 every\f1 platform. For \f0 a list of \fs18 the supported versions, see .NET Framework System Requirements.\par}";
GoToFirstPositionAndHighlightToolbar();
}
private void LoadData()
{
LoadRichTextEditorData();
}
private void LoadRichTextEditorData()
{
string[] availableFontFamilies;
//check to see if fonts are installed on machine
try
{
availableFontFamilies = new string[] {
new FontFamily("Arial").Name,
new FontFamily("Microsoft Sans Serif").Name,
new FontFamily("Tahoma").Name,
new FontFamily("Times New Roman").Name
};
}
catch (ArgumentException e)
{
throw new Exception("Font not present: " + e.Message);
}
List < object > availableFontSizes = new List < object >();
for (float i = 8; i <= 14; i++)
availableFontSizes.Add(i);
cmbFontFamily.Items.AddRange(availableFontFamilies);
cmbFontSize.Items.AddRange(availableFontSizes.ToArray());
}
private void ckbBold_CheckedChanged(object sender, EventArgs e)
{
if (_maskChanges)
return;
ChangeOrSetFont(string.Empty, null, FontStyle.Bold, ckbBold.Checked);
txtFunctionality.Focus();
}
private void ckbItalic_CheckedChanged(object sender, EventArgs e)
{
if (_maskChanges)
return;
ChangeOrSetFont(string.Empty, null, FontStyle.Italic, ckbItalic.Checked);
txtFunctionality.Focus();
}
private void ckbUnderline_CheckedChanged(object sender, EventArgs e)
{
if (_maskChanges)
return;
ChangeOrSetFont(string.Empty, null, FontStyle.Underline, ckbUnderline.Checked);
txtFunctionality.Focus();
}
private void cmbFontFamily_SelectedIndexChanged(object sender, EventArgs e)
{
if (_maskChanges)
return;
ChangeOrSetFont(cmbFontFamily.SelectedItem.ToString(), null, null, null);
txtFunctionality.Focus();
}
private void cmbFontSize_SelectedIndexChanged(object sender, EventArgs e)
{
if (_maskChanges)
return;
ChangeOrSetFont(null, float.Parse(cmbFontSize.SelectedItem.ToString()), null, null);
txtFunctionality.Focus();
}
private void ChangeOrSetFont(string familyName, float? emSize, FontStyle? fontStyle, bool? enableFontStyle)
{
if (txtFunctionality.SelectionType == RichTextBoxSelectionTypes.Empty)
{
SetSelectionFont(familyName, emSize, fontStyle, enableFontStyle);
}
else
{
ChangeFontStyleForSelectedText(familyName, emSize, fontStyle, enableFontStyle);
}
}
private void SetSelectionFont(string familyName, float? emSize, FontStyle? fontStyle, bool? enableFontStyle)
{
Font renderedFont = RenderFont(txtFunctionality.SelectionFont, familyName, emSize, fontStyle, enableFontStyle);
txtFunctionality.SelectionFont = renderedFont;
}
private void ChangeFontStyleForSelectedText(string familyName, float? emSize, FontStyle? fontStyle, bool? enableFontStyle)
{
_maskChanges = true;
try
{
int txtStartPosition = txtFunctionality.SelectionStart;
int selectionLength = txtFunctionality.SelectionLength;
if (selectionLength > 0)
using (RichTextBox txtTemp = new RichTextBox())
{
txtTemp.Rtf = txtFunctionality.SelectedRtf;
for (int i = 0; i < selectionLength; ++i)
{
txtTemp.Select(i, 1);
txtTemp.SelectionFont = RenderFont(txtTemp.SelectionFont, familyName, emSize, fontStyle, enableFontStyle);
}
txtTemp.Select(0, selectionLength);
txtFunctionality.SelectedRtf = txtTemp.SelectedRtf;
txtFunctionality.Select(txtStartPosition, selectionLength);
}
}
finally
{
_maskChanges = false;
}
}
///
/// Changes a font from originalFont appending other properties
///
/// Original font of text
/// Target family name
/// Target text Size
/// Target font style
/// true when enable false when disable
/// A new font with all provided properties added/removed to original font
private Font RenderFont(Font originalFont, string familyName, float? emSize, FontStyle? fontStyle, bool? enableFontStyle)
{
if (fontStyle.HasValue && fontStyle != FontStyle.Regular && fontStyle != FontStyle.Bold && fontStyle != FontStyle.Italic && fontStyle != FontStyle.Underline)
throw new System.InvalidProgramException("Invalid style parameter to ChangeFontStyleForSelectedText");
Font newFont;
FontStyle? newStyle = null;
if (fontStyle.HasValue)
{
if (fontStyle.HasValue && fontStyle == FontStyle.Regular)
newStyle = fontStyle.Value;
else if (originalFont != null && enableFontStyle.HasValue && enableFontStyle.Value)
newStyle = originalFont.Style | fontStyle.Value;
else
newStyle = originalFont.Style & ~fontStyle.Value;
}
newFont = new Font(!string.IsNullOrEmpty(familyName) ? familyName : originalFont.FontFamily.Name,
emSize.HasValue ? emSize.Value : originalFont.Size,
newStyle.HasValue ? newStyle.Value : originalFont.Style);
return newFont;
}
private void txtFunctionality_SelectionChanged(object sender, EventArgs e)
{
if (_maskChanges)
return;
if (string.IsNullOrEmpty(txtFunctionality.Text))
{
//clear all text with its ex-formatting
txtFunctionality.Clear();
LoadAndSetDefaultFont();
}
else
{
ScanSelectedTextAndHighlightToolbar();
}
}
private void txtFunctionality_KeyDown(object sender, KeyEventArgs e)
{
if (_maskChanges)
return;
if (e.Control && e.KeyCode == Keys.B)
{
ckbBold.Checked = !ckbBold.Checked;
e.Handled = true;
}
else if (e.Control && e.KeyCode == Keys.I)
{
ckbItalic.Checked = !ckbItalic.Checked;
e.Handled = true;
e.SuppressKeyPress = true; //avoid executing 'Insert TAB' for CTRL + I
}
else if (e.Control && e.KeyCode == Keys.U)
{
ckbUnderline.Checked = !ckbUnderline.Checked;
e.Handled = true;
}
}
private void GoToFirstPositionAndHighlightToolbar()
{
_maskChanges = true;
try
{
if (!string.IsNullOrEmpty(txtFunctionality.Text))
{
txtFunctionality.Suspend();
txtFunctionality.Select(0, 1);
using (RichTextBox txtTemp = new RichTextBox())
{
txtTemp.Rtf = txtFunctionality.SelectedRtf;
Font currFont = txtTemp.SelectionFont;
HighlightToolbar(currFont.FontFamily.Name, currFont.Size, currFont.Bold, currFont.Italic, currFont.Underline);
}
txtFunctionality.Select(0, 0);
txtFunctionality.Resume();
}
else
{
LoadAndSetDefaultFont();
}
}
finally
{
_maskChanges = false;
}
}
private Font GetFontFromToolbar()
{
FontStyle toolbarFontStyle = new FontStyle();
if (ckbBold.Checked)
toolbarFontStyle |= FontStyle.Bold;
if (ckbItalic.Checked)
toolbarFontStyle |= FontStyle.Italic;
if (ckbUnderline.Checked)
toolbarFontStyle |= FontStyle.Underline;
Font font = new Font(cmbFontFamily.SelectedItem.ToString(), (float)cmbFontSize.SelectedItem, toolbarFontStyle);
return font;
}
//could be changed into an extentension
public string TrimLastChar(string text)
{
if (text.Length >= 1)
return text.Substring(0, text.Length - 1);
else
return text;
}
private void LoadAndSetDefaultFont()
{
Font font = txtFunctionality.Font;
HighlightToolbar(font.FontFamily.Name, font.Size, font.Bold, font.Italic, font.Underline);
SetSelectionFont(font.FontFamily.Name, font.Size, font.Style, null);
}
private void ScanSelectedTextAndHighlightToolbar()
{
_maskChanges = true;
try
{
if (txtFunctionality.SelectionType == RichTextBoxSelectionTypes.Empty)
{
int selectionStart = txtFunctionality.SelectionStart != 0 ? txtFunctionality.SelectionStart - 1 : 0;
int selectionEnd = txtFunctionality.SelectionStart;
txtFunctionality.Suspend();
//case when passes to a new line - it looses font style so must get from Tooolbar
if (TrimLastChar(txtTextContent.Text).EndsWith("\n"))
{
txtTextContent.Select(selectionStart, 1);
txtTextContent.SelectionFont = GetFontFromToolbar();
txtTextContent.Select(selectionEnd, 0);
}
else
{
txtTextContent.Select(selectionStart, 1);
using (RichTextBox txtTemp = new RichTextBox())
{
txtTemp.Rtf = txtTextContent.SelectedRtf;
Font currFont = txtTemp.SelectionFont;
HighlightToolbar(currFont.FontFamily.Name, (float)Math.Truncate(currFont.Size), currFont.Bold, currFont.Italic, currFont.Underline);
txtTextContent.SelectionFont = currFont;
}
txtTextContent.Select(selectionEnd, 0);
}
txtFunctionality.Resume();
}
else
if (!string.IsNullOrEmpty(txtFunctionality.SelectedText))
{
int txtStartPosition = txtFunctionality.SelectionStart;
int selectionLength = txtFunctionality.SelectionLength;
if (selectionLength > 0)
using (RichTextBox txtTemp = new RichTextBox())
{
txtTemp.Rtf = txtFunctionality.SelectedRtf;
if (selectionLength < 2)
{
FontFamily firstCharFontFamily = txtTemp.SelectionFont.FontFamily;
float firstCharSize = txtTemp.SelectionFont.Size;
bool isBold = txtTemp.SelectionFont.Bold;
bool isItalic = txtTemp.SelectionFont.Italic;
bool isUnderline = txtTemp.SelectionFont.Underline;
HighlightToolbar(firstCharFontFamily.Name, firstCharSize, isBold, isItalic, isUnderline);
}
else
{
txtTemp.Select(0, 1);
FontFamily firstCharFontFamily = txtTemp.SelectionFont.FontFamily;
float firstCharSize = txtTemp.SelectionFont.Size;
bool isBold = txtTemp.SelectionFont.Bold;
bool isItalic = txtTemp.SelectionFont.Italic;
bool isUnderline = txtTemp.SelectionFont.Underline;
bool sameFontFamily = true, sameFontSize = true;
for (int i = 1; i < selectionLength; i++)
{
txtTemp.Select(i, 1);
sameFontFamily = txtTemp.SelectionFont.FontFamily.Name == firstCharFontFamily.Name;
sameFontSize = txtTemp.SelectionFont.Size == firstCharSize;
isBold = isBold && txtTemp.SelectionFont.Bold;
isItalic = isItalic && txtTemp.SelectionFont.Italic;
isUnderline = isUnderline && txtTemp.SelectionFont.Underline;
if (!sameFontFamily && !sameFontSize && !isBold && !isItalic && !isUnderline)
break;
}
HighlightToolbar(sameFontFamily ? firstCharFontFamily.Name : string.Empty,
sameFontSize ? firstCharSize : (float?)null,
isBold, isItalic, isUnderline);
}
}
}
}
finally
{
_maskChanges = false;
}
}
private void HighlightToolbar(string commonFamilyName, float? emSize, bool? isBold, bool? isItalic, bool? isUnderline)
{
if (!string.IsNullOrEmpty(commonFamilyName))
cmbFontFamily.SelectedItem = commonFamilyName;
else
cmbFontFamily.SelectedItem = null;
if (emSize.HasValue)
cmbFontSize.SelectedItem = (float)Math.Truncate(emSize.Value);
else
cmbFontSize.SelectedItem = null;
if (isBold.HasValue)
{
ckbBold.CheckState = isBold.Value ? CheckState.Checked : CheckState.Unchecked;
}
else
ckbBold.CheckState = CheckState.Unchecked;
if (isItalic.HasValue)
{
ckbItalic.CheckState = isItalic.Value ? CheckState.Checked : CheckState.Unchecked;
}
else
ckbItalic.CheckState = CheckState.Unchecked;
if (isUnderline.HasValue)
{
ckbUnderline.CheckState = isUnderline.Value ? CheckState.Checked : CheckState.Unchecked;
}
else
ckbUnderline.CheckState = CheckState.Unchecked;
}
}
}
namespace System.Windows.Forms
{
public static class ControlExtensions
{
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern bool LockWindowUpdate(IntPtr hWndLock);
//Method used agains flickering
public static void Suspend(this Control control)
{
LockWindowUpdate(control.Handle);
}
public static void Resume(this Control control)
{
LockWindowUpdate(IntPtr.Zero);
}
}
