Currently, I have a TabLayoutPanel with a few tabs, inside of each tab is a set of breadcrumbs. I would like to be able to display my breadcrumbs right next to the tabs (inside the TabBar itself). I haven't yet seen any instance of someone having done this, and I'm beginning to believe I might end up rewriting their TabLayoutPanel class myself and implementing that where needed, but obviously I'd rather not go that route unless there's no alternative.
Anyone have any guidance on this?
Just came across the same problem. Here are most of the relevent code snippets. I added a Unicode arrow when the tab was selected, and removed it when the tab was deselected.
private final String htmlStr ="\u25bb";
private String getTabTitle(String html){
// Designed to work for this example input.
//If you pass a different string you will need to do different matching.
if(html.indexOf("\u25bb") < 0)
return html;
else
return html.substring(html.indexOf("\u25bb")+1);
}
#Override
public void onBeforeSelection(BeforeSelectionEvent<Integer> event) {
if(!getSelectedIndex().equals(event.getItem())) {
notifyCurrentTabOfClosing();
selectedIndex = event.getItem();
String tabtitle = getTabTitle(getTabBar().getTabHTML(selectedIndex));
getTabBar().setTabHTML(selectedIndex, htmlStr+tabtitle);
}
}
}
public void selectTab(Widget widget) {
int widgetIndex = getWidgetIndex(widget);
selectTab(widgetIndex);
String tabtitle = getTabTitle(getTabBar().getTabHTML(widgetIndex));
getTabBar().setTabHTML(widgetIndex, htmlStr+tabtitle);
}
Related
In a GWT web app, I am using a DataGrid to manage elements from a database. I represent a list of elements as rows, the columns being editable fields of their characteristics (id, name, description). I am mostly using the EditTextCell class.
I now want to create a custom cell, for a column that has to represent a list of "tags" that can be attached to every element. From this cell, tags could be added, using a + button (that makes a drop-down menu appear or something), and deleted. Each tag should be a kind of button, or interactive widget (I later want to display pop-up with info, trigger actions, etc).
Actually, it would not be so different from the "tags" bar on the Stack Overflow website...
So I have been looking for a solution:
I thought this would be easy to do. I imagined just putting a FlowPanel in the cell, adding/removing Buttons/Widgets dynamically. But it turns out that in GWT Widgets and Cells and very different objects apparently..
I read making use of the AbstractCell class to create a custom cell allows to do anything, but its working is very low level and obscure to me.
I saw that CompositeCell allows to combine various cell widgets into one cell, but I have not found if it is possible to do it dynamically, or if the widgets are going to be the same for all lines throughout a column. I mostly saw examples about, for instance, how to put two Buttons in every cell of a single column.
What is the easiest way to implement what I need?
EDIT:
So, after some tests, I am going for Andrei's suggestion and going "low-level", creating a custom cell extending AbstractCell<>. I could create an appropriate "render" function, that generates a list of html "button", and also attaches Javascript calls to my Java functions when triggering a Javascript event (onclick, onmouseover, onmouseout...).
It is working pretty well. For instance, by clicking the "+" button at the end a tag list, it calls a MenuBar widget that presents the list of tags that can be added.
But I am struggling to find a way to update the underlying data when adding a tag.
To sum up:
I have a CustomData class that represents the data I want to display in each line of the table. It also contains the list of tags as a Set.
ModelTable (extends DataGrid) is my table.
CustomCell (extends AbstractCell) can renders the list of tags as several buttons on a line.
A click on a "+" button in a cell makes a AddTagMenu popup drop down, from which I can click on the tag to add.
How do I update the content of the cell?
I tried playing around with onBrowserEvent, onEnterKeyDown, bus events... with no success. At best I can indeed add a tag element to the underlying object, but the table is not updated.
It's not possible to meet your requirements without going really "low-level", as you call it.
It's relatively easy to create a cell that would render tags exactly as you want them. Plus icon is also easy, if this is the only action on the cell. However, it is very difficult to make every tag within a cell an interactive widget, because the DataGrid will not let you attach handlers to HTML rendered within a cell. You will need to supply your own IDs to these widgets, and then attach handlers to them in your code. The problem, however, is that when the DataGrid refreshes/re-renders, your handlers will most likely be lost. So you will have to attach them again to every tag in every cell on every change in the DataGrid.
A much simpler approach is to create a composite widget that represents a "row", and then add these "rows" to a FlowPanel. You can easily make it look like a table with CSS, and supply your own widget that looks like a table header. You will need to recreate some of the functionality of the DataGrid, e.g. sorting when clicked on "column" header - if you need this functionality, of course.
As you have already noted, using CompositeCell could be a way to get what you want.
The idea is to create a cell for every tag and then (during rendering) decide which one should be shown (rendered). Finally combine all those cells into one by creating a CompositeCell.
The main disadvantage of this solution is that you need to know all possible tags before you create a DataGrid.
So, if you have a fixed list of possible tags or can get a list of all existing tags and this list is reasonably small, here is a solution.
First, we need to know which tag is represented by a column so I extended a Column class to keep information about a tag. Please, note that TagColumn uses ButtonCell and also handles update when the button is clicked:
public class TagColumn extends Column<DataType, String> {
private TagEnum tag;
public TagColumn(TagEnum tag) {
super(new ButtonCell());
this.tag = tag;
setFieldUpdater(new FieldUpdater<DataType, String>() {
#Override
public void update(int index, DataType object, String value) {
Window.alert("Tag " + getTag().getName() + " clicked");
}
});
}
public TagEnum getTag() {
return tag;
}
#Override
public String getValue(DataType object) {
return tag.getName();
}
}
Then create a cell for each tag (I have hard-coded all tags in a TagEnum):
List<HasCell<DataType, ?>> tagColumns = new ArrayList<HasCell<DataType, ?>>();
for(TagEnum tag : TagEnum.values())
tagColumns.add(new TagColumn(tag));
Now, the most important part: decide either to show the tag or not - overwrite render method of the CompositeCell:
CompositeCell<DataType> tagsCell = new CompositeCell<DataType>(tagColumns) {
#Override
protected <X> void render(Context context, DataType value, SafeHtmlBuilder sb, HasCell<DataType, X> hasCell) {
if(value.getTagList().contains(((TagColumn) hasCell).getTag()))
super.render(context, value, sb, hasCell);
else
sb.appendHtmlConstant("<span></span>");
}
};
This is important to always render any element (for example empty span when the tag should not be shown). Otherwise the CompositeCell's implemantation will get confused when accessing sibling elements.
Finally, full, working example code:
private DataGrid<DataType> getGrid() {
DataGrid<DataType> grid = new DataGrid<DataType>();
List<HasCell<DataType, ?>> tagColumns = new ArrayList<HasCell<DataType, ?>>();
for(TagEnum tag : TagEnum.values())
tagColumns.add(new TagColumn(tag));
CompositeCell<DataType> tagsCell = new CompositeCell<DataType>(tagColumns) {
#Override
protected <X> void render(Context context, DataType value, SafeHtmlBuilder sb, HasCell<DataType, X> hasCell) {
if(value.getTagList().contains(((TagColumn) hasCell).getTag()))
super.render(context, value, sb, hasCell);
else
sb.appendHtmlConstant("<span></span>");
}
};
Column<DataType, DataType> tagsColumn = new Column<DataType, DataType>(tagsCell) {
#Override
public DataType getValue(DataType object) {
return object;
}
};
grid.addColumn(tagsColumn, "Tags");
grid.setRowData(Arrays.asList(
new DataType(Arrays.asList(TagEnum.gwt)),
new DataType(Arrays.asList(TagEnum.table, TagEnum.datagrid)),
new DataType(Arrays.asList(TagEnum.datagrid, TagEnum.widget, TagEnum.customCell)),
new DataType(Arrays.asList(TagEnum.gwt, TagEnum.table, TagEnum.widget, TagEnum.customCell)),
new DataType(Arrays.asList(TagEnum.gwt, TagEnum.customCell)),
new DataType(Arrays.asList(TagEnum.gwt, TagEnum.table, TagEnum.datagrid, TagEnum.widget, TagEnum.customCell))
)
);
return grid;
}
public class TagColumn extends Column<DataType, String> {
private TagEnum tag;
public TagColumn(TagEnum tag) {
super(new ButtonCell());
this.tag = tag;
setFieldUpdater(new FieldUpdater<DataType, String>() {
#Override
public void update(int index, DataType object, String value) {
Window.alert("Tag " + getTag().getName() + " clicked");
}
});
}
public TagEnum getTag() {
return tag;
}
#Override
public String getValue(DataType object) {
return tag.getName();
}
}
public class DataType {
List<TagEnum> tagList;
public DataType(List<TagEnum> tagList) {
this.tagList = tagList;
}
public List<TagEnum> getTagList() {
return tagList;
}
}
public enum TagEnum {
gwt ("gwt"),
table ("table"),
datagrid ("datagrid"),
widget ("widget"),
customCell ("custom-cell");
private String name;
private TagEnum(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
I'm trying to implement a custom perspective switcher toolbar to replace eclipse's built-in one. I couldn't get the toolbar to display, and it was shown to me that due to a bug with the dynamic element in a menu contribution, I have to use a control element instead, as described in the workaround to the dynamic bug.
I have a toolbar displaying following that approach, but I cannot figure out how to update it dynamically. The workaround instruction is to call ContributionItem#fill(CoolBar, int) from my WorkbenchControlContributionItem's update method instead of doing the fill in the createControl method.
I don't know who is supposed to call update, but it never gets invoked no matter what I do. I have a perspective listener which knows when to update the toolbar, so from that listener's callback I call fill(CoolBar, int). But I wasn't sure how to get the CoolBar to pass to that method, so I created one on the current shell.
The end result of all this is that the toolbar displays the correct number of items initially, but when I need to add an item, it has no effect. I call fill(CoolBar, int) and it adds the new item to the toolbar, but everything I've tried to make the CoolBar and ToolBarupdate does not work. When I re-launch the app, the toolbar has the added item.
I'm sure I'm doing this wrong, but I can't figure out the right way. Here's an elided representation of my code (omitting methods, layout code, etc not related to the update problem).
public class PerspectiveSwitcherToolbar extends WorkbenchWindowControlContribution implements IPerspectiveListener {
...
#Override
protected Control createControl(Composite parent) {
this.parent = parent;
IWorkbenchPage page = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
page.getWorkbenchWindow().addPerspectiveListener(this);
toolBarManager = (ToolBarManager)parent.getParent().getData();
fTopControl = new Composite(parent, SWT.BORDER);
fill(new CoolBar(page.getWorkbenchWindow().getShell(), SWT.HORIZONTAL), -1);
return fTopControl;
}
#Override
public void fill(CoolBar coolbar, int index) {
IPerspectiveDescriptor[] openPerspectives = page.getOpenPerspectives();
String activePerspective = getPerspectiveId();
ToolBar toolbar = new ToolBar(fTopControl, SWT.NONE);
for(IPerspectiveDescriptor descriptor : openPerspectives) {
ToolItem item = new ToolItem(toolbar, SWT.RADIO);
//overkill here, trying to find some way to upate the toolbar
toolbar.update();
parent.update();
parent.layout(true);
parent.getParent().update();
parent.getParent().layout(true);
coolbar.layout(true);
}
//PerspectiveListener callback
#Override
public void perspectiveActivated(IWorkbenchPage page, IPerspectiveDescriptor perspective) {
fill(new CoolBar(page.getWorkbenchWindow().getShell(), SWT.HORIZONTAL), -1);
if (page.getWorkbenchWindow() instanceof WorkbenchWindow){
//this non-API call doesn't help either
((WorkbenchWindow) page.getWorkbenchWindow()).updateActionBars();
}
}
...
}
Is there any way to SuggestBox to CellTable? Maybe there is another solution then SuggestBox?
I need to get an editable cell with suggestion feature?
I'm using GWT 2.4.
I don't think you can add it directly in. Try using a ClickableTextCell as the cell for that column. Then code your ValueUpdater (which will be called when the cell is clicked) to open up a DialogBox. Put your SuggestBox, and other widgets (OK button, Cancel button, and such), inside that DialogBox. Initialize the SelectionBox with the current contents of the cell. The DialogBox will likely be a DialogBox subclass with extra state data you initialize with the object for that CellTable row as well as the field for that column, so that the OK action knows what field on what object to update with the new contents of the SuggestBox. Essentially it's a popup editor. Not ideal, because users will expect the editor to be embedded in the CellTable, but there are only a few cell editors available (EditTextCell, DatePickerCell, SelectionCell and CheckboxCell, and maybe another variant of text editing), but I've used this technique, and really, it's not too bad.
I ended up using FlexTable instead of CellTable. With FlexTable you may put any widget inside a table cell.
I needed this also and found a solution (under testing, but solong it is working):
I copied the Code from TextInputCell into a new Class SuggestBoxTextInputCell
public class SuggestBoxTextInputCell extends AbstractInputCell<String, SuggestBoxTextInputCell.ViewData> {
MySuggestBox suggestBox;
and added some lines to the onBrowserEvent method:
// Ignore events that don't target the input.
InputElement input = getInputElement(parent);
String eventType = event.getType();
if (BrowserEvents.FOCUS.equals(eventType)) {
TextBox textBox = new MyTextBox(input);
suggestBox = new MySuggestBox(getSuggestOracle(), textBox);
suggestBox.onAttach();
}
Element target = event.getEventTarget().cast();
The classes MySuggestBox and MyTextbox exist only to make the needed constructor and methods public:
private class MyTextBox extends TextBox {
public MyTextBox(Element element) {
super(element);
}
}
private class MySuggestBox extends SuggestBox {
public MySuggestBox(SuggestOracle suggestOracle, TextBox textBox) {
super(suggestOracle, textBox);
}
#Override
public void onAttach() {
super.onAttach();
}
}
getSuggestOracle() only delivers the needed SuggestOracle. Hope someone can use this solution.
I needed this as a solution so I play around with the solution provided by Ande Hofer.
The exact same issue met by Ankit Singla, when the suggestbox is working fine when I press "Enter" key, but not from the "Mouse Click".
I go on further and add-on this onto the solution.
if (BrowserEvents.FOCUS.equals(eventType)) {
...
...
suggestbox.addSelectionHandler(new SelectionHandler<Suggestion>() {
#Override
public void onSelection(SelectionEvent<Suggestion> event) {
Suggestion selectedSuggestion = event.getSelectedItem();
String selectedValue = selectedSuggestion.getReplacementString();
onSuggestSelected(input, selectedValue, valueUpdater);
}
});
suggestbox.onAttach();
}
and a private function
private void onSuggestSelected(Element input, String value,
ValueUpdater<String> valueUpdater) {
input.blur();
suggestbox.onDetach();
if (suggestbox.getSuggestionDisplay().isSuggestionListShowing()) {
((DefaultSuggestionDisplay) suggestbox.getSuggestionDisplay()).hideSuggestions();
}
valueUpdater.update(value);
}
So far so good.
I am trying to create a ListBox using GWT. I am using UiBinder to create the field.
I would like to set a default text on the list box and when a user clicks on the box, it should show me the list items. Once again, if user has not selected any option, it should show me the default text again.
Any way to do this either using Uibinder or some ListBox methods?
If I understand correctly you want a value to show but when the user clicks on the list it disappears and shows you the list items?
As far as I know there is no option to that natively.
What you can do is add the first item to hold your default value.
You can do this grammatically by using addItem in code or using:
<g:Listbox>
<g:item value="-1">Default text</g:item>
</g:Listbox>
works with gwt 2.1+
The value can still be selected.
You can choose to ignore it or add an attribute "disabled" with value "disabled" to the option element:
listbox.getElement().getFirstChildElement().setAttribute("disabled" ,"disabled" )
hope it helps a bit :)
You can also use a renderer to control what is shown if 'Null' is selected.
(Inspired by: How do I add items to GWT ListBox in Uibinder .ui.xml template ?)
private class SimpleRenderer implements Renderer<T>{
private String emptyValue = "Select a value";
#Override
public String render(T val) {
if(val == null) {
return emptyValue;
}
return val.toString();
}
#Override
public void render(T val, Appendable appendable) throws IOException {
appendable.append(render(val));
}
public void setEmptyValue(String emptyValue) {
this.emptyValue = emptyValue;
}
}
GWT's CellBrowser is a great way of presenting dynamic data.
However when the browser contains more rows than some (seemingly) arbitrary maximum, it offers a "Show More" label that the user can click to fetch the unseen rows.
How can I disable this behavior, and force it to always show every row?
There are several ways of getting rid of the "Show More" (which you can combine):
In your TreeViewModel, in your NodeInfo's setDisplay or in the DataProvider your give to the DefaultNodeInfo, in onRangeChange: overwrite the display's visible range to the size of your data.
Extend CellBrowser and override its createPager method to return null. It won't change the list's page size though, but you can set it to some very high value there too.
The below CellBrowser removes the "Show More" text plus loads all available elements without paging.
public class ShowAllElementsCellBrowser extends CellBrowser {
public ShowAllElementsCellBrowser(TreeViewModel viewModel, CellBrowser.Resources resources) {
super(viewModel, null, resources);
}
#Override
protected <C> Widget createPager(HasData<C> display) {
PageSizePager pager = new PageSizePager(Integer.MAX_VALUE);
// removes the text "Show More" during loading
display.setRowCount(0);
// increase the visible range so that no one ever needs to page
display.setVisibleRange(0, Integer.MAX_VALUE);
pager.setDisplay(display);
return pager;
}
}
I found a valid and simple solution in setting page size to the CellBrowser's builder.
Hope this will help.
CellBrowser.Builder<AClass> cellBuilder = new CellBrowser.Builder<AClass>(myModel, null);
cellBuilder.pageSize(Integer.MAX_VALUE);
cellBrowser = cellBuilder.build();
The easiest way to do this is by using the:
cellTree.setDefaultNodeSize(Integer.MAX_VALUE);
method on your Cell Tree. You must do this before you begin expanding the tree.
My workaround is to navigate through elements of treeview dom to get "show more" element with
public static List<Element> findElements(Element element) {
ArrayList<Element> result = new ArrayList<Element>();
findShowMore(result, element); return result; }
private static void findShowMore(ArrayList res, Element element) {
String c;
if (element == null) { return; }
if (element.getInnerText().equals("Show more")) { res.add(element);
}
for (int i = 0; i < DOM.getChildCount(element); i++) { Element
child = DOM.getChild(element, i); findShowMore(res, child); } }
and than use:
if (show) { element.getStyle().clearDisplay(); } else {
element.getStyle().setDisplay(Display.NONE); }