I need a scrollPanel with a verticalpanel and a tablayout panel inside it. Problem is, unless I specify the exact height of the tablayoutPanel, the tab content does not show. Any known fixes/ workarounds?
Not the answer you are looking for, but might spark an idea for another way to do this - what does it mean to scroll a tab panel? As soon as the user starts scrolling down, the tabs will no longer be visible to change tabs, user will always need to scroll all the way to the top to consider any other tab.
That said, any of the *LayoutPanel classes GWT has introduced that implement ProvidesResize, RequiresResize, etc need sizing to properly draw themselves and their content. This is why you are having the issue. These classes are designed to size their children, not to just consume as much space as those children require.
Closest I can suggest to a workaround (except for putting a ScrollPanel inside the TabLayoutPanel instead) would be to know the height of the current tab's contents, add to that the height of just the tabs themselves, and assign that as the height of the tabpanel. Not a very nice solution, but it might get you by.
Related
We have many screens where different types of GWT panels are used.
One common problem across many screens is that, content size is derived at runtime. So, if I define a height for a panel(Vertical/Horizontal/DockPanel) and when any new components are getting added within panel or content is more, panel height remains the same. So we are not able to see the contents. UI look and feel becomes worst.
How do we handle the height problems? Do we have to manually code to adjust every panel/widget height when something gets changed in screen. Is it not a very bad way of coding?
Also, now we have datagrids at some places, if no of records are very less, we see a huge space left out below datagrid, not sure how do we handle these cases?
Updated below with few examples as per the comment:
Do you mean to say that whenever we know that content grows vertically, we can always choose FlowPanel. Because, some of the screens we have used Vertical panel/Horizontal Panel and inside that when user clicks something a new fields getting added and shown. So Vertical Panel/Horizontal Panel height automatically not getting adjusted. One more example is that we have main Vertical Panel within a Dock Layout Panel content area and inside that there are some widgets whose content may vary. So now if I use a FlowPanel to the content which varies in size, what about outer panels? Will get it adjusted? Again to say the kind of panels we have used - Dock Layout Panel is used with fixed header, footer, left menu and Content area. A scroll panel is used within Content area. All our different widgets go inside this which is mix and match of horizontal/vertical/datagrids..etc.
In GWT (and HTML) you can either set the height of a panel or let it expand naturally. In general, once you set the height of something, you lose the ability to let it expand naturally.
Some Panels in GWT implicitly set their own height (or require that you set their height) and so are never good choices for dynamically sized content. LayoutPanels and ScrollPanels, for example, can never adjust dynamically, and expect you to provide size information programmatically. FlowPanels and HTMLPanels, on the other hand, are great for dynamic heights and would rather you not set their height explicitly.
If you want a scrolling panel, of course you have to define how high it should be - how else could it know when to scroll and when to just get bigger? But, you can put a FlowPanel (which expands automatically) inside a ScrollPanel (which you have set at 800px or whatever). Then, as you add content to the FlowPanel, it will expand inside the ScrollPanel. Users can then scroll to see different parts of the FlowPanel.
Trouble-shooting tips:
Make sure you aren't setting the height on panels that you want to expand naturally
Make sure you ARE setting the height on panels that should always be the same size
Try using FlowPanels instead of Horizontal/VerticalPanels
*LayoutPanels and AbsolutePanels always need explicit sizes and can never grow dynamically as you add more content. Anything you want to grow with content should probably be a FlowPanel or HTMLPanel.
I'm trying to come up with way to animate a page change on a CellTable in GWT which would work the same way as changing tabs on (http://gwt.google.com/samples/Showcase/Showcase.html#!CwTabLayoutPanel). In other words the new table page would slide in from the top (or bottom for that matter).
The CellTable uses a SimplePager to initiate the page change at the moment.
Thanks, Matyas
There's no way to do that in simple way, because to make slide animation you have to have at least 2 already rendered pages: first one that is shifted out and second one that replaces first. In showcase example with animated tabset all tabs are rendered and are ready to use, but CellTable with SimplePager has no rendered pages except visible one - new page is simply rendered just directly into CellTable body.
So, if you really want to create such effect using CellTable and Pager, you have to implement your own pair of CellTable and Pager that will do following:
Keep 2 containers with rendered rows: one is visible, second is hidden.
CellTable body should have viewport (just a <div> with "overflow:hidden" CSS rule) that will have both containers inside.
When pager change page, you have to force CellTable to render new rows into hidden container.
When new data was rendered, place your hidden container into proper position to make illusion that it continues visible one, and make it visible;
Provide animation that will move both containers into new positions. I'd recommend do not use coding for animations (e.g. Timer) - much better and effective to use CSS3 transformation rules (see "CSS3 transform Property" and/or "CSS3 transition Property").
When animation finished, make first container hidden and switch pointers to visible and hidden containers - so that you return to initial state.
Hope this helps.
I want to create a custom panel/layout and it's seeming pretty impossible at this point. I need the components to start in the upper left corner and stack downward until they fill the panel vertically, then wrap to the top of the next column and so on until they eventually fill the screen and create a horizontal scrollbar. After an entire day of trying I've decided it's only possible by abusing GWT (and I assume the whole web browser) adding crippling complexity and terrible performance. Please let me know if I'm missing something and layout like this is possible. Thank you!
Lame solution: Have a small (almost invisible) AbsolutePanel where every string is displayed within a div and measured (getClientWidth/height()). Then each panel can calculate it's size based on the strinsg, borders, padding, etc. it contains. Once each panel knows it's size, they can be layed out relative to the sizes of the other panels in the contianer.
Check out FlexTable, which allows you to specify the row,column for the widget to be added
I want to have a panel, with two columns.
The first column will contain a list of beans, and the right one a form panel for editing those beans. What I want to do, is that list height is the same as height of the form panel on the right. My list of beans will be larger and larger over time, so it's height will probably exceed form height. When that happens, there should be a scrollbar showed for the list. I also don't want to set explicit size for list and my form panel (it should be flexible because some time I will add or remove some form fields).
I'm basically new to GXT. I'm looking forward for some proposals.
Cheers,
jjczopek
Try setting the CSS style overflow-y: auto; with max-hight on the Panel (div?) on which you need a scroll bar. That should solve your problem.
Try to set Fill or Fit Layout.
I Am trying to create a Tab Panel where I can add and delete tabs on demand.
Where I am getting stuck is that if a potential user adds too many tabs the new tabs go off the screen.
Each Tab is to contain a text area widget where a user may enter text.
Is there any way of horizontally scrolling the just the TabBar and not the whole browser window?
I could use a scroll panel but I was hoping to scrol just the Tabs, not the panel contents.
I cannot see any available method in the com.google.gwt.user.client.ui.TabPanel API that will perform this function and no real way to split the panel.
Help!
It's not what you've asked for, but you might consider using a StackPanel instead of a TabPanel, since if the user can enter a long list of items it's generally better to have vertical scrolling instead of horizontal scrolling.
The gwt TabPanel isn't the greatest, and there's not a real easy way to do what you want. You could take a look at the tab widget in Ext-GWT, which scrolls the tabs, but I don't think extjs is generally a good idea.
There's a bunch of new layout-based widgets arriving with GWT 2.0. Look at TabLayoutPanel. It places tabs in a very wide container inside a div with overflow=hidden. You might be able to add some controls to scroll that container and get the effect you want.
Good luck, and report back if you get something working. GWT really needs more widget contributors.