Im writing a tool that simulates Turing machines.
Here, Ive got a transition table of a such a machine
When a cell is double-clicked, a little dialog pops up (which is a custom widget, derived from QFrame) and should allow editing the contens of a cell. A cell may contain several rules (those |q2, 3, R| and such) and I want that little dialog to show these. The thing is that a user should be able to add and remove rules. At first, I wanted to use QLabels for that, which is fine with the adding aspect, but how do I remove existing rules? I planned having the user select the rules and click "Remove" but do I make sure the entire rule (QLabel) is selected?
Or should I take a completely ddifferennt approach to removing? Like letting every label have an own checkbox?
I would like to keep it as simple as possible. For example, QTableWidget is too "fat" for this, I feel like
You should use a QListWidget - this will allow multiple lines, multiple selection, without the cells or horizontal/vertical headers.
http://qt-project.org/doc/qt-4.8/qlistwidget.html
Related
I'm writing a GUI using QT for embedded system with linux. This device has no mouse. Only display and specific keyboard with keys: up, down, return and 7 number keys.
The software will be used to set some parameters of device and read them (some charts also).
Example of how menu could look:
after OPTION 1 selected
After SUBOPTION 1 selected some table with data is loaded.
Sometimes after selecting option i need to load specific widget and sometimes just another set of options.
I think it is possible to implement custom labels and kind of list widget that aligns them.
I guess it is also possible to use Qt's MVC classes for it. They are highly customizable, but i never made custom views and delegates.
Maybe i just need to create QtListView with stringlist model and apply stylesheet to it so it gets look more like buttons. And based on selection in list load next widget.
Which way is better and why?
Is there any easier ways to accomplish this?
Any ideas would be appreciated.
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.
Is there a way to control the order of slides displayed to users in a carousel from the Experience Editor perspective? (or even the Content Editor)
Basically, based on the user that has been identified or not identified, I would like to display a different slide as the first slide of the carousel. All the other slides would still be present, just in a different, specified order.
Is there a way to accomplish this via rules or should I look at having to create separate datasources that have the different slide orders already specified?
TL;DR
Personalization can do three things:
vary a datasource for a rendering
vary a rendering (use another rendering basically)
hide a rendering.
I guess the question you need to answer is whether what you need can be accomplished by doing either one of these actions.
If you've used nested structures to represent your carousel (like we do in SCORE, you can see how it looks like here or here) it's not hard to show/hide certain panels based on personalization conditions and thus reorder the carousel. Depending on how exactly it looks on the published site you may only need to repoint datasources. Either way, it's personalization out of the box and your content structures working nicely together.
If you've used a (variation of a) MultiList field to represent a list of your panels with panels themselves being items somewhere in the shared content area it's not something personalization engine can change based on a condition. Changing a field value is, unfortunately, not on the menu. I am sure you can code around it thanks to Sitecore being so open and flexible but I am not sure you can make it seamless (e.g. variations preview in Page Editor).
Rendering parameters is also not something you can change but if yours are static and defined on the rendering definition item (as opposed to being supplied when component is bound to the placeholder and thus recorded inside the presentation details) you can get away with having two definition items for your carousel component (same code behind it) and picking the right one based on the personalization condition.
Hope it helps.
I'm creating a control that can be used for manual inspection of Tesseract-OCR's output.
Currently I've implemented it as a custom widget, where I do all the drawing (I use a QScrollArea to handle the scrolling at least), and it looks like this:
As you can see, the images are "flowing", like word-wrapped lines in a text editor, and I use the space below the header text, so I don't have 2 clearly separated columns.
Now, it was suggested to me that using a custom widget is 'reinventing the wheel', but the problem is, I don't see a clear way to customize one of the existing container widgets enough to look and behave like this, that would involve significantly less effort or code. Neither is it clear at all to me what is the best way to do it. At most, I can think of using a QListWidget with owner-drawn items and variable item heights.
Am I wrong to use a custom widget here?
We have a list that uses a custom renderer containing a label, a checkbox and two icons (which have click events). This list needs to be made WCAG 2.0 compliant and in order to do that we need the list to be keyboard navigable.
The problem is with being able to move from one list item to the next and have the focus move to the label for the next/previous list item. Specifically, when the user enters the list using TAB button, the label for the first list item receives focus (highlighted box around text) and the entire row in the list is highlighted as the selected item.
However, when the user then presses the down arrow key to move to the next list item, the next row becomes highlighted (is now the selected item) but the focus remains on the label of the previous row (highlight still shown around label for row 1). The only way to get the focus to move to the newly selected row is to tab through the checkbox and two icons. This isn't a big deal if there are only a couple list items but would be a pain if there are 20+ rows in the list.
Is there a way to get the focus to move to the label of the newly selected row as soon as the user moves (using up/down cursor keys) to the new list item? I know a picture would help but I don't have anyway of posting a screenshot online. Any help would be greatly appreciated.
You're going to have to dig into how focus works in Flex. This is not a complete answer, but hopefully you can put together a solution that works for you. I did this about 4-5 years ago in Flex 3, but it should be similar in Flex 4.
How Focus Works in Flex
The main things to know are the FocusManager singleton class and the IFocusManagerComponent interface.
The FocusManager moves the focus around the UI based on user interactions (mouse clicks, keyboard navigation, etc.).
If a component implements the IFocusManagerComponent interface, then the FocusManager will include it in the "tab" loop and allow the component to be focused via keyboard navigation.
How Focus Works With Flex List Components
You've already stumbled onto the peculiarities of how focus works with the List component and item renderers. The Flex List components implement IFocusMangerComponent and so when you tab through the UI the FocusManager sends the focus to the list.
The List may or may not focus the item renderers. In Flex 3 you had to be using editable item renderers for this to happen, it may or may not be the same in Flex 4.
Some Ideas for Solutions to Your Problem
I think there are numerous ways to solve this. Use some combination of these techniques:
override the protected keyDownHandler() method of the List component. I don't have the code handy, but if you look at it's implementation in the List class you should be able to make your overridden version set the focus on the next renderer.
use methods of the FocusManager to find components in the tab loop: getNextFocusManagerComponent(), findFocusManagerComponent(). Check the docs there are others that will be useful. For example, when the user presses the down arrow, you can let the next item renderer get selected, then use findFocusManagerComponent() (passing in the newly selected renderer) and then tell the FocusManager to focus it with the setFocus() method. This is probably not exactly the right approach ;)
By the way, the FocusManger is a Flex singleton object, every UIComponent in Flex has a focusManager property you can use to get a reference to it.
consider disabling focus on objects that don't need to receive focus (like the Label in your item renderer). There are numerous properties to do this: focusEnabled, hasFocusableChildren, mouseFocusEnabled, tabEnabled, tabChildren etc.
consider disabling focus on the List component, but then making your item renderers implement the IFocusManagerComponent interface. Implementing the interface is simple, you just declare it in your class (there's no actual methods to implement). The tricky part will be now your item renderers need to have key down handlers (just override the protected keyDownHandler() method that all UIComponent objects have).
I think there are other techniques you can use, it's just been too long since I did this. I'd be happy to provide more help if you get stuck somehwere...