I'm using QTextEdit from C++ Qt5. I want to properly split and show rich text in numerated pages similarly to how it's done in Microsoft Word. I've tried document->setPageSize, however that does not work for me - text is still shown in one continuous page.
AFAIK QTextEdit doesn't support the word-processor-style concept of "pages". Rather, QTextEdit is designed around editing and viewing a continuous document, whose only delineation is at the level of "blocks" (i.e. paragraphs).
Note this telling comment in the QTextDocument::print(QPagedPaintDevice *) const method-documentation of the QTextDocument class:
If the document is not paginated, like for example a document used in
a QTextEdit, then a temporary copy of the document is created and the
copy is broken into multiple pages according to the size of the paint
device's paperRect().
Related
I'm using wxWidgets for a log window of a piece of software which runs for many hours. The log can accumulate 10,000's of entries. Does the community have a suggestion for how not to have the GUI thread choke for many seconds when updating a textctrl or richtextctrl with this many lines? I'm open to using either control type but richtext is preferable to I can highlight warnings or errors.
It's currently set to readonly, so undo, redo, paste, etc are not active. I'm currently freezing and thawing it before and after adding content.
In a test case, I add 10000 lines to the text control with a freeze and thaw before and after. This operation still takes over a minute. Are these text controls simply incapable of handling long content?
Assuming your display is like a log, where each "line" is it's own entry, try using the wxListCtrl in "virtual mode". Basically, you maintain the data in your own control (a vector, array, whatever works) and the control asks you for only the data that is currently visible.
Inherit wxListCtrl with your own class and implement OnGetItem. When a row is visible, your derived control will have this method called for each row (and each column if you implement multiple columns) and you provide it with the data for that row, accessed directly from your array (list, vector, whatever).
More information is available in the wxWidgets docs here: http://docs.wxwidgets.org/3.0/classwx_list_ctrl.html#a92370967f97215e6068326645ee76624
The suggestion to use wxListCtrl in #avariant answer is a good one, however a wxTextCtrl with wxTE_RICH style should still be capable of appending 10000 lines in well less than a minute if you freeze/thaw it before/after. I'd be curious to know if you can reproduce the problem in the text sample included with wxWidgets (which already has a menu item doing something like this) and, if so, which wxWidgets port do you use.
My problem is quite simple: I need to transfer form elements from one tab to another.
Say I've ten tabs and each tab has it's own set of text edits.
Is it possible to create just one set of text edits and transfer it from one tab to another,changing functionality behind it, but without changing the forms layout?
Currently I've "solved" that problem just by populating copy of text edit's for each tab but common sense tells me that there's a simpler way to achieve that in Qt.
I'm using Qt 5.7.
Yes, it's possible using a single QTabBar. A QTabBar, as its name suggests, only displays a narrow bar with multiple tabs within.
You can put a frame below that tab bar and listen for tab change signal which is emitted by the QTabBar. In this way, the frame below is the same for all tabs, so you can change underlying logic for each tab.
I need a QTabWidget with icons only:
How can I hide the label text of a tab in Qt? I cannot set the text to an empty string (""), as I am using docked widgets ( QDockWidget ) and the label text is set automatically (and I need it if the widget is floating).
But in tabbed mode I just want to display the icons (of the tabs).
Possible approaches:
Font size to 0?
I need to create my own bar class and override the paint event as here
Anything easier / cleaner?
--- Edit ---
Ok, the "set window title to empty string, and reset it the original text" approach works. I am using the topLevelChanged signal for this. However, it has some drawbacks, as the empty text still occupies some space. Another issue, with the text the tooltip is gone, and I cannot set it back.
What I am currently trying is something in-between the "text empty" and Prasad Silva's approach. I try to identify the text label inside the tab and set its size to 0, then reset it. It's slightly different, but would keep the text intact.
Btw, I see a line on top of my tabs, any idea what this is (where it comes from)?
Edit: There seems to be no "easy way" (style sheet, attribute) for this, see Hiding bottom line in QTabBar
Maybe I will create the whole tab bar on my own, as the automatically generated stuff is just too hard to handle (agree with PS on this).
This can not be done easily. Use empty text.
The way I solved something like was to create a QDockWidget subclass that installed a QWidget subclass as the titlebar (via setTitleBarWidget). This gave me control over showing/hiding the text in the titlebar when the dock widget fires topLevelChanged, dockLocationChanged and visiblityChanged.
This is really a big hack to get around the fact that Qt has refused to expose a public API for the docking system. We have since moved on to a custom docking implementation due to these limitations.
If you do not want to see the text, you can set it to an empty text after saving the current text, and when you want to see it again, restore it from the stored variable.
I do not think there is anything in the API for this not so common case, which means you will need to do it yourself.
Now, you could claim that it is tedious to do for many widgets, but on the other hand, you could write a simple hash define or inline function to do this repetitive work for you, which would only result a one-liner call, basically, which you would need to use anyway when changing the state.
I have a problem with displaying a text to area with different attributes.
My project has a multi-threading build. I reach to GUI text area by using signal-slot mechanism. I put my texts to the text area like this;
addrMW->ui->printerArea->appendPlainText(command.Data);
I want to append my text to this area with different font, size, etc..
I'm using Qt Creator 2.7.2 / Qt 5.1. Could someone explain this to me with an example?
What you want is a rich text edit. Luckily QTextEdit is able to handle that. Check the acceptRichText property (which should be true by default).
Then the methods you're looking for are:
setCurrentCharFormat
setCurrentFont
setFontFamily
setFontPointSize
etc...
Then, instead of appendPlainText() you should use append() to add text to the QTextEdit. Also see this Q/A. As proposed in the accepted answer, you can also use html formatted text instead.
What is exactly richtext and how do I format data in richtext in QTextEdit?
The internal rich text format is tag/attribute-based, and is similar to HTML using in-line CSS style="xxx" attributes. The default export/import format (using toHTML/setHTML) is a subset of HTML. See this link:
http://doc.trolltech.com/4.6/richtext-html-subset.html
Note that CSS classes are not supported internally and are converted to their representing attributes at import.
QTextEdit can display text that is formatted with additional layout and style information (i.e. enriched) which can be set either programatically or by using a subset of HTML.
The Rich Text Processing documentation gives you an overview and pointers to more in-depth information.
If you're looking for a WYSIWYG toolbar for the QTextEdit, you'll end up disappointed. There is no default one (although the SDK contains an example app). So you should either make the toolbar yourself or find one.