I am working on a flex app that uses XML templates to dynamically create DisplayObjects. These templates define different layouts that can be used for each page of content in the app (ie , 2 columns, 3 columns etc etc). The administrator can select from one of these and populate each area with their content.
The templates add one of 3 types of DisplayObject - HBox, VBox or a third component - LibraryContentContainer (an mxml component that is defined as part of the app) - which is effectively a canvas element with a TextArea inside.
The problem that I am getting is that I need each of these areas to automatically resize to fit the length of the content but don't seem to be able to find an effective way to do so.
In the LibraryContentContainer, when the value of the TextArea is set, I am calling .validateNow() on the LibraryContentContainer. I then set the height property on both the TextArea and LibraryContentContainer to match the textHeight property of the TextArea.
In the following example, this is the LibraryContentContainer, viewer is the TextArea and the value property of the TextArea is bound to this.__Value. v is the variable containing the content for the textarea
this.__Value = v;
this.validateNow();
this.viewer.height = this.viewer.textHeight;
this.height = this.viewer.height;
This works to a degree in that the TextArea grows or shrinks depending on the length of content, but it's still not great - sometimes there are still vertical scrollbars even tho the size of the TextArea has grown.
Anyone got any ideas?
Thanks
Adam
I think the problem lies not with your dynamically added components, but with the component they're being added to. How is the height of this component being determined? If you set verticalScrollPolicy and horizontalScrollPolicy on this container to off, do your scrollbars disappear? If that's the case, then you'll need to look at how this component is sized rather than your hbox, vbox, or whatever it is you're adding.
Related
When I run my program it will display all content properly, and when I resizing the main window, the layout along with all associated widgets remain fixed, rather than resizing with the main window. I used to increase my all widget and listWidget respect to window computer resolution size but still this not one work properly.
I used this one code finding the system height and width.
QWidget widget;
widget.resize(widget.width(), widget.minimumHeight());
QRect rec = QApplication::desktop()->screenGeometry();
int h = rec.height();
int w = rec.width();
// Increasing the listwidget size
ui->listWidget->setFixedHeight(h);
ui->listWidget->setFixedWidth(w);
//increasing the button size
ui->pushButton->setFixedHeight(h0.2);
ui->pushButton->setFixedWidth(w0.2);
At this link you will find two screenshots that illustrate my problem.
Please resolve to solve my problem. Thanks very much in advance.
When defining the layout of your windows and forms in Qt Designer you have to define each element of your form in advance, in order to have a working layout.
This solution is based on the screenshots provided in the comments to the question. Follow these steps:
Add an empty widget to the central area of your form, if there is nothing there. It will be used as a placeholder for the controls you will add later, and of course you can replace it with whatever widget you want. But you need it there to define a proper layout.
In the property panel, set the horizontal QSizePolicy of this widget to MinimumExpanding.
Add an horizontal spacer to the left side of your progress bar.
Define a minimum/maximum width for the white widget on the left (I guess it's a text area). As an example set the maximum width to 200
pixels.
Make the same for the QTabWidget on the right.
Give a minimum height to the Groupbox on top.
Then give the grid layout to the MainWindow.
You should get something similar in the designer view (I use a dark theme, yours will have different colors of course):
If you complete all steps you should have a nicely resizing window.
For the future: remember to integrally define your layouts, also using placeholder widgets when needed, read carefully the documentation about the widgets size policies (there are several, you need to play with them to fully understand each one) and keep in mind that Qt uses a container based approach which is different, as an example from those used by the .Net framework that relies on the concept of anchors.
EDIT : to answer questions in the comments
You will need to add a layout to any widget that contains other widgets, e.g. adding controls to your groupbox will require to give it a grid, horizontal or vertical layout in order to scale nicely on resize. Again use spacers and size policies to make it look the way you want. If you need to add or remove controls, or change their positions, you may need to brake the layout, rearrange and then set it again.
You can also select groups of widgets and give them a layout e.g. vertical, than another group and set them horizontal and so on... then give a grid layout to the container widget to build a compound layout.
There are endless possibilities, you just need to practice and go through trial and error as for everything else...
You can also do it all programmatically, check the Qt widgets documentation for this. But for complex layouts I would not go that way: it's a lot of code... and you have to compile and run to test every modification.
Using the QtCreator, within the designer you can simply right-click on the parent-widget and add a Grid-Layout.
This one resizes it's children to it's dimensions.
I know I can fix this programmatically and I know I could set the text to tighten / scale but I would like to know how to get this text to extend organically to a third line on small screens. How can I accomplish that?
There are a couple of things you need to take care of before your label grows:
Make sure the 'number of lines' field in the attributes inspector is set to zero. Setting it zero allows the label to grow depending upon the content it has.
If the label is in a container view, make sure you haven't specified the height constraint explicitly on the container view. Since the container view should generate its height from its subviews and the subviews will generate their height from the content they have. Its sort of a chain process that goes on if you have a deeper hierarchy.
Make sure there is no sibling view to the container view with an explicit height that might cause your container view to shrink while maintaining its own height. This point may also apply even if your label is not within some container view.
In the image below, the container view(gray one) is bound from three sides allowing it to grow from the bottom.
Below image shows the constraints applied to the content views of the container. The container is driving its height from its content views.
Below I have increased the text of the label from a single line to three lines. At this point the label tries to expand horizontally but since the container view is bind with the super view on both sides the label has only one direction left to increase itself. It increases downwards pushing the textfield and button down and since the button is tied with the bottom of the container view it pulls the container view increasing its height.
In particular I have a GWT project with a
TextArea element which I want to conform to a set width and expand as much as needed to the bottom.
ListBox element which I want to conform to a set width and expand vertically to show the entirety of the displayed list item.
Those are two widgets using replaced elements: <textarea> and <select> respectively.
for the TextArea, there's no way to make it really "resize automatically" other than listening to events and computing the new size (there's actually no need to compute the new size, you can just let the browser do it; see http://phaistonian.pblogs.gr/expanding-textareas-the-easy-and-clean-way.html)
for the ListBox, it's impossible to have the items' text wrap. See Word wrap options in a select list for a similar question in pure JS.
Set the width to whatever number and set height to auto.
Is there a way to make the layoutStretch property always be obeyed? E.g. I have it set to "1,3,2", but then a widget (a label) in the first part (the "1" in "1,3,2") expands (when more text is added), and then the 1:3:2 ration is no longer respected. That is, the "1:3:2" ratio turns into something more like "3:1:3".
You should take a look at the property QWidget::sizePolicy. It controls how the layout respects the sizeHint() of its children when it updates the geometries.
So what you need to do is: Make the layout ignore the horizontal sizeHints of the child widgets by setting the horizontal sizePolicy of the three child widgets to QSizePolicy::Ignored:
QLabel *label = ...;
...
label->setSizePolicy(QSizePolicy::Ignored, label->sizePolicy().verticalPolicy());
(The second argument will ensure that the vertical policy isn't changed by this statement.
Of course, you should set the size policy of every child widget, this example code is only for the label.)
Note that the contents of your layout have to be widgets; I think nested layouts can't be assigned a size policy (but I might be wrong). At least using QtDesigner, there is no way of applying a size policy to a layout itself (if it isn't the layout of a widget). See comments for details.
In QtDesigner, you can set the sizePolicy of the child widgets like this:
Before:
Shrinked:
Select the items in the layout:
Set the horizontal size policy to "Ignored":
Result:
I have the following scenario :
A Flex 3 DataGrid is sitting here
At runtime, a column is added to this grid
The column has a custom ItemRenderer
The ItemRenderer inherits from HBox, and adds a few items to the HBOx dynamically
My problem is that the width of the column doesn't change. As a consequence, my column stays small, and an ugly horizontal scrollbar is displayed in the line, instead of my content (which is completely unreadable).
I would like the column to adapt its width to the content of the HBox in the ItemRenderer. I tried the following :
Setting the 'percentWidth' of the ItemRenderer to '100'
Invalidating the properties of the ItemRenderer after adding the items
The only thing that has a "visible" effect it to force the width of the DataGridColumn. Obviously this is not acceptable since I'm dynamically adding components to the ItemRenderer, and I don't know how many or how big they are.
Besides, when I am in the ItemRenderer, I have no access to the column itself (or do I ?) so I cannot force the size of the column from here.
So is there a way around this ? Would AdvancedDataGrid help here (notwhistanding the fact that I cannot really use it for other reasons ...)
Alternatively, I would be happy enough if someone has a solution where the column cell is displayed without the ugly horizontal scrollbar (don't mention setting horizontalScrollPolicy to "off", been there, tried that, lost shirt ;) ).
Thanks
PH
I did not found a solution for the size, however I found the way to remove the scrollbar ; you must put the "horizontalScrollPolicy : 'off'" in the list of properties of the itemRenderer Factory (rather then on the itemRenderer itself).