I am learning Xamarin forms.
I wanted to be able to bind some ViewModel to some values in a DataManager class (Singleton).
Say the Singleton is a BleManager and all ViewModel need to use it to get or set some information to or from the BLE device.
I Know how to bind my VM to the XAML view code.
But now I need to be able to get the viewModels to update local Data when the BLEManager updates some info, like battery level.
so for example (semi sudo-code).
public class BLEInterface: INotifyPropertyChanged
{
protected virtual void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
public async Task<float> GetDeviceName()
{
await Task.Delay(1000);
return float.random(0f:100f)
}
}
public sealed class BLEManager: INotifyPropertyChanged
{
private static BLEManager shared;
private static object objectLockCheck = new Object();
private BLEInterface BleModel { get; set; }
private float batteryLevel;
public float BatteryLevel {
get => batteryLevel;
set {
batteryLevel = value;
OnNotifyPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnNotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
private BLEManager()
{
}
public async Task ConnectToBLE()
{
await Task.Delay(1000);
BleModel = new TestModel();
}
public async void GetBatteryLevel()
{
BatteryLevel = await bleModel.GetDeviceName();
}
public static BLEManager Shared
{
get
{
if(shared == null)
{
lock (objectLockCheck)
{
if(shared == null)
{
shared = new BLEManager();
}
}
}
return shared;
}
}
}
The Part I need to know is how can my viewModel hook on changes from the BleManager battery level property.
I want to add the functionality of value change handler to my customize class that extends the DateBox. I had already added the key handler but I also want to implement the value change handler to the same class.
I want my DateBox to work properly when I take input from DatePicker or Keyboard.
Any other suggestion will also be helpful.
public class ValidationDateBoxInternal extends DateBox implements KeyUpHandler{
private List<String> regexList;
public ValidationDateBoxInternal(){
super();
this.getTextBox().addKeyUpHandler(this);
regexList = new ArrayList<String>();
}
public void setAsNotEmpty() {
regexList.add(DateValidation.isNotEmpty);
isValid();
}
public void setAsValidDate(){
regexList.add(DateValidation.isValidDate);
isValid();
}
public void onKeyUp(KeyUpEvent event) {
isValid();
}
public void setText(String text) {
super.getTextBox().setText(text);
isValid();
}
public void clearRegexList() {
regexList.clear();
}
public String getText() {
if (regexList.size() == 0) {
return super.getTextBox().getText();
}
if (isValid()) {
for (String regex: regexList) {
if (regex.equals(DateValidation.isValidDate)) {
return super.getTextBox().getText().toLowerCase().trim();
}
}
return super.getTextBox().getText().trim();
}
else {
return null;
}
}
public boolean isValid() {
for (String regex: regexList) {
if (!DateValidation.isValid(super.getTextBox().getText(), regex)) {
this.addStyleName("invalid");
return false;
}
}
this.removeStyleName("invalid");
return true;
}
}
Your class extends DateBox, which implements the HasValueChangeHandlers interface. So you can call:
DateBox.addValueChangeHandler(ValueChangeHandler<java.util.Date> handler)
For example:
public class MyDateBox extends DateBox implements ValueChangeHandler<Date> {
void foo() {
addValueChangeHandler(this);
}
void onValueChange(ValueChangeEvent<Date> event) {
// validate the value of the DateBox
}
}
So, I have values in getter setter variables when I click on form submit but now want to have those values in variables and check combination of them to run code from another java class
I have tried using parametrized constructor or may be having a common setter but that did not help.
package com.grt.dto;
import java.util.Set;
public class WDPayrollRecon {
public Set<String> dataType;
public String planCountry;
public String payPeriod;
public String currentPeriod;
public String lastPayPeriod;
Set<String> test;
public Set<String> getdataType() {
return dataType;
}
public void setdataType(Set<String> dataType) {
this.dataType = dataType;
System.out.println("this is dataType" +dataType);
test = dataType;
}
public String getPlanCountry() {
return planCountry;
}
public void setPlanCountry(String planCountry) {
this.planCountry = planCountry;
}
public String getPayPeriod() {
return payPeriod;
}
public void setPayPeriod(String payPeriod) {
this.payPeriod = payPeriod;
}
public String getCurrentPeriod() {
return currentPeriod;
}
public void setCurrentPeriod(String currentPeriod) {
this.currentPeriod = currentPeriod;
}
public String getlastPayPeriod() {
return lastPayPeriod;
}
public void setlastPayPeriod(String lastPayPeriod) {
this.lastPayPeriod = lastPayPeriod;
}
public WDPayrollRecon()
{
}
public WDPayrollRecon(Set<String> dataType,String planCountry,String payPeriod,String currentPeriod,String lastPayPeriod)
{
this.dataType = dataType;
this.planCountry = planCountry;
this.payPeriod = payPeriod;
this.currentPeriod = currentPeriod;
this.lastPayPeriod = lastPayPeriod;
if(dataType.contains("GTLI")& planCountry.equals("USA")){
System.out.println("This is test");
}
else{
System.out.println("This is not test");
}
}
}
I have created a table using table viewer and now i need to filter based on the text entered in the text box so how can we filter the table the code to create table is as follows
TableViewerColumn message = new TableViewerColumn(viewer, SWT.NONE);
message.getColumn().setWidth(800);
message.getColumn().setText("Message");
message.setLabelProvider(new ColumnLabelProvider()
{
#Override
public void update(ViewerCell cell)
{
Object element = cell.getElement();
if(element instanceof MyObject)
{
MyObject obj = (MyObject) element;
cell.setText(obj.getMessage());
}
}
});
}
private static class MyObject
{
private String first;
private String second;
private String message;
public MyObject(String first, String second,String message)
{
this.first = first;
this.second = second;
this.message = message;
}
public String getFirst()
{
return first;
}
public void setFirst(String first)
{
this.first = first;
}
public String getSecond()
{
return second;
}
public void setSecond(String message)
{
this.second = second;
}
public String getMessage()
{
return message;
}
public void setMessage(String message)
{
this.message = message;
}
so now how can we filter the table. Please help me as I am new to jface table viewer
Use a class derived from ViewerFilter to add a filter:
class MyFilter extends ViewerFilter
{
#Override
public boolean select(Viewer viewer, Object parentElement, Object element)
{
MyObject obj = (MyObject)element;
// TODO return true to include the object, false to exclude
}
}
Add this to the table with:
viewer.addFilter(new MyFilter());
Call
viewer.refresh();
to get the viewer to rerun the filter when the text changes.
I want to fire the "open root node" event on my current working CellTree, which now has the following behaviour:
#Override
public <T> NodeInfo<?> getNodeInfo(final T value) {
return new DefaultNodeInfo<Categoria>(
(value instanceof Categoria) ?
createBranchDataProvider((Categoria)value) :
rootDataProvider,
new CategoriaCell()
);
}
private AsyncDataProvider<Categoria> createRootDataProvider() {
AsyncDataProvider<Categoria> dataProvider = new AsyncDataProvider<Categoria>() {
#Override
protected void onRangeChanged(HasData<Categoria> display) {
AsyncCallback<Categoria[]> cb = new AsyncCallback<Categoria[]>() {
#Override
public void onSuccess(Categoria[] result) {
updateRowCount(result.length, true);
updateRowData(0, Arrays.asList(result));
}
#Override
public void onFailure(Throwable caught) {
Window.alert(caught.toString());
}
};
rpcService.getCategorie(cb);
}
};
return dataProvider;
}
How can I fire that "onRangeChanged" event, to refresh my level-1 nodes?
What is my convenience method missing?
private void updateTree() {
TreeNode rootTreeNode = cellTree.getRootTreeNode();
for (int i = 0; i < rootTreeNode.getChildCount(); i++) {
rootTreeNode.setChildOpen(i, false);
}
// HOW TO REFRESH LEVEL-1 NODES?
}
Working example. Add reference to DataProvider (and parent Node) (MyMenuItem and MyCell with DataProvider in my code). After adding element refresh parent.
public class MyMenuItem {
private String name;
private String action; //some data
private int level; //if needed
private ArrayList<MyMenuItem> list; //nodes childrens
private MyMenuItem parent; //track internal parent
private MyCell cell; //for refresh - reference to visual component
public void setCell(MyCell cell) {
this.cell = cell;
}
public void refresh() {
if(parent!=null) {
parent.refresh();
}
if (cell!=null) {
cell.refresh(); //refresh tree
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAction() {
return action;
}
public void setAction(String action) {
this.action = action;
}
public MyMenuItem(String name, String action) {
super();
parent = null;
level = 0;
this.name = name;
this.action = action;
list = new ArrayList<MyMenuItem>();
}
public MyMenuItem(String name) {
this(name, "");
}
public void addSubMenu(MyMenuItem m) {
m.level = this.level+1;
m.parent = this;
list.add(m);
}
public boolean hasChildrens() {
return list.size()>0;
}
public int getLevel() {
return level;
}
public void setLevel(int level) {
this.level = level;
}
public ArrayList<MyMenuItem> getList() {
return list;
}
public MyMenuItem getParent() {
return parent;
}
}
public class MyTreeModel implements TreeViewModel {
private MyMenuItem officialRoot; //default not dynamic
private MyMenuItem studentRoot; //default not dynamic
private MyMenuItem testRoot; //default not dynamic
private MyMenuItem root;
public MyMenuItem getRoot() { // to set CellTree root
return root;
}
public MyTreeModel() {
root = new MyMenuItem("root");
// Default items
officialRoot = new MyMenuItem("Official"); //some basic static data
studentRoot = new MyMenuItem("Student");
testRoot = new MyMenuItem("Test");
root.addSubMenu(officialRoot);
root.addSubMenu(studentRoot);
root.addSubMenu(testRoot);
}
//example of add add logic
private void addNew(MyMenuItem myparent, String name, String uid) {
myparent.addSubMenu(new MyMenuItem(name, uid));
myparent.refresh(); //HERE refresh tree
}
#Override
public <T> NodeInfo<?> getNodeInfo(T value) {
ListDataProvider<MyMenuItem> dataProvider;
MyMenuItem myValue = null;
if (value == null) { // root is not set
dataProvider = new ListDataProvider<MyMenuItem>(root.getList());
} else {
myValue = (MyMenuItem) value;
dataProvider = new ListDataProvider<MyMenuItem>(myValue.getList());
}
MyCell cell = new MyCell(dataProvider); //HERE Add reference
if (myValue != null)
myValue.setCell(cell);
return new DefaultNodeInfo<MyMenuItem>(dataProvider, cell);
}
#Override
public boolean isLeaf(Object value) {
if (value instanceof MyMenuItem) {
MyMenuItem t = (MyMenuItem) value;
if (!t.hasChildrens())
return true;
return false;
}
return false;
}
}
public class MyCell extends AbstractCell<MyMenuItem> {
ListDataProvider<MyMenuItem> dataProvider; //for refresh
public MyCell(ListDataProvider<MyMenuItem> dataProvider) {
super("keydown","dblclick");
this.dataProvider = dataProvider;
}
public void refresh() {
dataProvider.refresh();
}
#Override
public void onBrowserEvent(Context context, Element parent, MyMenuItem value,
NativeEvent event, ValueUpdater<MyMenuItem> valueUpdater) {
if (value == null) {
return;
}
super.onBrowserEvent(context, parent, value, event, valueUpdater);
if ("click".equals(event.getType())) {
this.onEnterKeyDown(context, parent, value, event, valueUpdater);
}
if ("dblclick".equals(event.getType())) {
this.onEnterKeyDown(context, parent, value, event, valueUpdater);
}
}
#Override
public void render(Context context, MyMenuItem value, SafeHtmlBuilder sb) {
if (value == null) {
return;
}
sb.appendEscaped(value.getName());
//add HERE for better formating
}
#Override
protected void onEnterKeyDown(Context context, Element parent,
MyMenuItem value, NativeEvent event, ValueUpdater<MyMenuItem> valueUpdater) {
Window.alert("You clicked "+event.getType()+" " + value.getName());
}
}
in module add
treeModel = new MyTreeModel();
tree = new CellTree(treeModel,treeModel.getRoot());
The Level-1 nodes (I suppose you the mean below the root node) can not be refreshed the way you are doing it.
You have to store the instance of your dataProvider for the level-1 nodes somewhere.
Later when you refresh your list you have to update your stored dataProvider for your level-1 nodes.
The nodes below the level-1 can be refreshed the way you are doing it. Because as soon as you close the level 1 nodes (that is what you are doing in the updateTree method) and the next time you open it getNodeInfo will be called and the updated Subcategories will be retrieved and displayed in the CellTree.
UPDATE
For refreshing the CellWidgets which is attached to AsyncDataProvider you will probably have to extend the AsyncDataProvider and either extract the RPC call to a getData() method which is called in the onRangeChanged() method or create an interface with a refresh method and implement it in your custom AsyncDataProvider which calls the protected onRangeChanged() method.