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Rich Text Editing in Java Printing ANSI/AIM Code 128 in Java Rich Text Editing

Rich Text Editing using barcode generation for servlet control to generate, create barcode 128 image in servlet applications. Basic Infromation about Micro QR Code This completes our sy swing ANSI/AIM Code 128 ntax highlighting example. Clearly we could use more sophisticated regular expressions, or even avoid them altogether and use a nite state automaton or a parser to identify which portions of each line require particular formatting. For large texts with complex syntax, syntax highlighting can be computationally expensive, but QSyntaxHighlighter helps to keep the overhead down by formatting only enough lines to correctly highlight the lines that are visible.

. A Rich Text Line Edit In some applications spring framework Code 128 Code Set A it is a requirement that users can enter single lines of rich text. For example, a database application may have a description eld where we want the user to be able to use bold, italic, and colors for particular words if they want. We will see examples of this in 14 and 16.

Unfortunately, PyQt does not provide such a widget. In this subsection we will create a RichTextLineEdit, a subclass of QTextEdit that provides the functionality we need; it is shown in Figure 13.2.

In the process we will learn how to programmatically format pieces of text in a QTextEdit, and how to iterate over a QTextEdit s QTextDocument to extract the text and its formatting.. Figure 13.2 The Rich Text Line Edit The rich text line ed swing barcode code 128 it will support the most common kinds of text formatting that apply to single lines: bold, italic, underline, strikeout, superscript, and subscript. In addition, three font styles will be supported monospaced, sans serif, and serif and the ability to set the text s color to a limited range of colors. We will begin with some static constants and the initializer.

. class RichTextLineEdi t(QTextEdit): (Bold, Italic, Underline, StrikeOut, Monospaced, Sans, Serif, NoSuperOrSubscript, Subscript, Superscript) = range(10) def __init__(self, parent=None): super(RichTextLineEdit, self).__init__(parent) self.monofamily = QString("courier") self.

sansfamily = QString("helvetica") self.seriffamily = QString("times") self.setLineWrapMode(QTextEdit.

NoWrap) self.setTabChangesFocus(True) self.setVerticalScrollBarPolicy(Qt.

ScrollBarAlwaysOff) self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff) fm = QFontMetrics(self.

font()) h = int(fm.height() * (1.4 if platform.

system() == "Windows" \ else 1.2)). 13. Rich Text and Printing self.setMinimumHeight (h) self.setMaximumHeight(int(h * 1.

2)) self.setToolTip("Press <b>Ctrl+M</b> for the text effects " "menu and <b>Ctrl+K</b> for the color menu"). We begin by setting s code 128a for Java ome default font families. Nowadays, every platform can be expected to provide Courier, Helvetica, and Times fonts (or fonts for which these names are aliases). Since the widget is a single line, we switch off line wrapping and scrollbars.

We also ensure that Tab causes a change of focus rather than the insertion of a Tab character. Calculating a minimum and maximum height will help when we implement the size hint methods, but it is complicated slightly by differences in font metrics across platforms. The tooltip is there to give users a hint that the widget has some special key presses.

Notice that the conditional expression is enclosed in parentheses. They are essential in this case, since without them, on non-Windows platforms, h would always be set to 1 instead of the 20 or 30 or so that we would expect..

def sizeHint(self): r eturn QSize(self.document().idealWidth() + 5, self.

maximumHeight()). Qt 4.2 The preferred size is the ideal width of the text (taking into account font sizes and attributes like bold and italic), with a bit of padding to give a little margin, and the maximum height. The QTextDocument.idealWidth() method was introduced with Qt 4.

2.. def minimumSizeHint(s j2se barcode standards 128 elf): fm = QFontMetrics(self.font()) return QSize(fm.width("WWWW"), self.

minimumHeight()). For the minimum size, we take the width of four W characters in the widget s default font. Alternatively, we could have simply used an arbitrary amount, say, 40 pixels. One thing that distinguishes the RichTextLineEdit from a QLineEdit is the user s ability to change the format and color of words and characters.

To support this we must provide some means by which the user can apply such changes. We have done this by providing a text effects menu and a color menu, and by supporting some key sequences for formatting. Both menus are invoked by particular key sequences, and the text effects menu is also popped up when a context menu event occurs.

. def contextMenuEvent( j2ee code 128 code set c self, event): self.textEffectMenu(). A context menu event occurs when the user right-clicks on some platforms, or presses a particular key or key sequence on others. In this case, we simply call the custom textEffectMenu() method, which will pop up a suitable menu. By.

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