How to place a control at the center of a canvas?
I have a main VLayout set to 100% width and 100% height. I want to place a grid at the center of this layout, meaning at the center of the browser's "viewport". How to do that with smartGWT layouts?
setLayoutAlign(Alignment.CENTER)
This places the controls center to the layout's breadth axis. But if I nest HLayout and VLayout it is not giving desired results.
you have to set the layoutAlign on all nested Layout panels.
the configuration is not inherited from parent panels and while HLayout defaults to TOP, VLayout defaults to LEFT.
Also, make sure that you call:
parentWidget.addMember(childWidget), instead of: parentWidget.addChild(childWidget)
The first one obeys setLayoutAlign(), but the last one doesn't.
Related
I have a border layout in ExtJS where there is a north panel which, in turn, has several panels nested in it.
The "parent" north panel is collapsible and has a splitter. The problem is, whenever I move the splitter, the other panels are repainted too late.
Example: if my panel is 300px and I resize it to 320px, my panels remain 300px. If i resize again to, say, 350px, the panels get resized to 320px.
The parent panel's layout mode is set to "auto" by default.
When I set the layout mode of the parent panel to "vbox", the other panels resize appropriately in width. However, these child-panels are expandable/collapsible as well, and with the vbox layout I can no longer expand them fluently.
Anyone have a clue what's going on/how to fix the lag?
Edit: after further investigation, it appears to only affect the headers of the panels, not the panels themselves.
I fixed it (for now) by adding the following to the parent panel, even though it's laggy...
listeners: {
resize: function() {
Ext.each(this.items.items, function(child){
var w = child.getWidth();
child.getHeader().setWidth(w);
});
}
}
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 build a GWT GUI, but I'm not sure if it's possible. Basically, I need to be able to stack three layouts/panels, one on top of another like this:
Bottom Layout: Panel that fills the whole screen (will actually contain SVG stuff).
Middle Layout: DockLayoutPanel with tools docked around the edges, also full screen.
Top Layout: Transparent panel, again filling the whole screen.
Is it possible to stack panels like this? I assume I could use AbsolutePanel to do it somehow, but I was hoping for a nicer solution.
Thanks,
Jon
Because you want a DockLayoutPanel inside, try with a LayoutPanel (or the RootLayoutPanel) and simply add your widgets in order as, by default, a child of a LayoutPanel fills its parent.
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.
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