I want to check if the first letter of string is in uppercase in Dart language. How can I implement it? Thanks in advance.
The simplest way I can think of is to compare the first letter of the string with the uppercase equivalent of it. Something like:
bool isUpperCase(String string) {
if (string == null) {
return false;
}
if (string.isEmpty) {
return false;
}
if (string.trimLeft().isEmpty) {
return false;
}
String firstLetter = string.trimLeft().substring(0, 1);
if (double.tryParse(firstLetter) != null) {
return false;
}
return firstLetter.toUpperCase() == string.substring(0, 1);
}
Updated the answer to take in consideration digits.
Also #Saed Nabil is right, this solution will return true if the string starts with any character that is not a letter (except for digits).
You can use the validators library if you are not already using it.
Then use this method
isUppercase(String str) → bool
check if the string str is uppercase
Don't forget to import the dependency, see documentation, to the pubspec.yaml and to your code import 'package:validators/validators.dart';.
Example code:
if(isUppercase(value[0])){
... do some magic
}
You should check that the value is not empty and not null first for safety. Like this:
if(value != null && value.isNotEmpty && isUppercase(value[0])){
... do amazing things
}
check this code it will return the actual uppercase letter else will return null
void main(){
var myString = "1s you said";
var firstCapital = firstCapitalLetter(myString);
if( firstCapital != null){
print("First Capital Letter is ${firstCapital}");
}else{
print("Not found");
}
}
String firstCapitalLetter(String myString){
final allCapitals = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; //string.substring(0, 1).toUpperCase() == string.substring(0, 1) will not work with for ex. numbers;
if (myString == null) {
return null;
}
if (myString.isEmpty) {
return null;
}
if (myString.trimLeft().isEmpty) {
return null;
}
if( allCapitals.contains(myString[0])){
return myString[0];
}else{
return null;
}
}
this is a typical case for Optional type of Java language , please check this library if you prefer functional style code
optional package
bool isUppercase(String str){
return str == str.toUpperCase();
}
This seems to be elegant way for checking uppercase
String s='Hello';
bool isUpper = isUppercase(s[0]);
print(isUpper); //true
isUpper = isUppercase(s[1]);
print(isUpper); //false
Add this extension
extension Case on String{
// isuppercase
bool isUpperCase(){
int ascii = codeUnitAt(0);
return ascii >= 65 && ascii <= 90;
}
// islowercase
bool isLowerCase(){
int ascii = codeUnitAt(0);
return ascii >= 97 && ascii <= 122;
}
}
use it like this
String letter = 'A';
print(letter.isUpperCase()); // true
While making my project I stuck on a problem.
I have the following thing:
This is in my PostComment action
comment = Emoticon.Format(comment);
Emoticon is public class.
The Format action return the following:
public static string Format(string input)
{
if (input == null || input.Length == 0)
{
return input;
}
else
{
string result = input;
Emoticon[] all = All;
foreach (Emoticon emoticon in all)
{
string a;
string a_;
int border;
// Decide whether a link is required.
if (emoticon.Url != null && emoticon.Url.Length > 0)
{
a = string.Format("<a href=\"{0}\">", emoticon.Url);
a_ = "</a>";
border = 1;
}
else
{
a = "";
a_ = "";
border = 0;
}
// Replace this emoticon.
string replacement =
string.Format(
"{0}<img src=\"{1}\" alt=\"{2}\" align=\"AbsMiddle\" border=\"{3}\" />{4}",
a,
emoticon.VirtualPath,
HttpUtility.HtmlEncode(emoticon.Title),
border,
a_);
result = result.Replace(emoticon.Shortcut, replacement);
}
return result;
}
}
And from PostComment action I go to view and print the comment:
<div class="panel-body">#comment.Content</div>
But my problem is in string.Format(
"{0}<img src=\"{1}\" alt=\"{2}\" align=\"AbsMiddle\" border=\"{3}\" />{4}", because it returns string and in the view it is a string but my purpose is to be a picture. #comment.Comment is also string.
i want to show all folders(images, videos,files) with directories/files, currently only show images folder with files, but other folder are not show. I try to find solution but not found. Here is the code & its screenshot(http://postimg.org/image/wm5ypbk9d/).
FileManager.java
package com.rim.samples.device.mapactiondemo;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.KeypadListener;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.component.TreeField;
import net.rim.device.api.ui.component.TreeFieldCallback;
import net.rim.device.api.ui.container.MainScreen;
public class FilesManager extends MainScreen {
FTPMessages _ftp = null;
String[] fileList;
// ..................
private final Bitmap openIcon = Bitmap.getBitmapResource("open.png");
private final Bitmap closedIcon = Bitmap.getBitmapResource("closed.png");
private final Bitmap movieIcon = Bitmap.getBitmapResource("movie.png");
private final Bitmap songIcon = Bitmap.getBitmapResource("song.png");
private final Bitmap playIcon = Bitmap.getBitmapResource("play.png");
private final Bitmap imgIcon = Bitmap.getBitmapResource("images.png");
String nodeTen;
int node10;
TreeField myTree;
String[] nodeData;
// ListField to be displayed - null - no Field displayed
// List of entries to be displayed - null or length = 0 means no entries
// protected so that another Thread can update this list....
protected ListDirectory[] _resultsList = null; // entries available for
// display
private ListDirectory _selectedEntry = null;
public FilesManager(FTPMessages ftp) {
super();
_ftp = ftp;
// Setting starting directory
try {
/*
* fileList = _ftp.list(); for (int i = 0; i < fileList.length; i++)
* { _ftp.cwd(fileList[i]); }
*/
_ftp.cwd("images");
_ftp.cwd("files");
_ftp.cwd("videos");
} catch (Exception e) {
}
this.setTitle("Server File List");
TreeCallback myCallback = new TreeCallback();
myTree = new TreeField(myCallback, Field.FOCUSABLE) {
protected boolean navigationClick(int status, int time) {
// We'll only override unvarnished navigation click behavior
if ((status & KeypadListener.STATUS_ALT) == 0
&& (status & KeypadListener.STATUS_SHIFT) == 0) {
final int node = getCurrentNode();
if (getFirstChild(node) == -1) {
// Click is on a leaf node. Do some default action or
// else fall through.
// Note: this will also detect empty folders, which
// might or
// might not be something your app has to handle
Dialog.alert("clicked " + getCookie(node));
// TODO: open player screen, etc.
return true;
}
}
return super.navigationClick(status, time);
}
};
myTree.setDefaultExpanded(false);
myTree.setRowHeight(openIcon.getHeight());
try {
node10 = myTree.addChildNode(0, _ftp.pwd());
} catch (Exception e) {
}
this.add(myTree);
refreshList();
}
private void refreshList() {
// TODO Auto-generated method stub
_resultsList = null;
String[] directory = null;
try {
directory = _ftp.list();
} catch (Exception e) {
}
if (directory != null && directory.length > 0) {
_resultsList = new ListDirectory[directory.length];
for (int i = 0; i < directory.length; i++) {
_resultsList[i] = new ListDirectory(directory[i],
ListDirectory.UNIX_SERVER);
}
}
if (_resultsList != null && _resultsList.length > 0) {
// we have some results
for (int i = 0; i < _resultsList.length; i++) {
String bb = directory[i];
String nodeFive = new String(bb);
this.myTree.addChildNode(node10, nodeFive);
}
} else {
}
}
private class TreeCallback implements TreeFieldCallback {
public void drawTreeItem(TreeField _tree, Graphics g, int node, int y,
int width, int indent) {
final int PAD = 8;
String text = (String) _tree.getCookie(node);
Bitmap icon = closedIcon;
if (text.endsWith(".mp3")) {
icon = songIcon;
} else if (text.endsWith(".avi")) {
icon = movieIcon;
} else if (text.endsWith(".png") || text.endsWith(".jpg")) {
icon = imgIcon;
} else if (_tree.getExpanded(node)) {
icon = openIcon;
}
g.drawBitmap(indent, y, icon.getWidth(), icon.getHeight(), icon, 0,
0);
// This assumes filenames all contain '.' character!
if (text.indexOf(".") > 0) {
// Leaf node, so this is a playable item (movie or song)
g.drawBitmap(_tree.getWidth() - playIcon.getWidth() - PAD, y
+ PAD, playIcon.getWidth(), playIcon.getHeight(),
playIcon, 0, 0);
}
int fontHeight = getFont().getHeight();
g.drawText(text, indent + icon.getWidth() + PAD,
y + (_tree.getRowHeight() - fontHeight) / 2);
}
}
}
The other classes that used with this code, download from that link(complete project classes)
http://remote.offroadstudios.com/files/filemanager.zip
you can also check files on server, ip:64.207.150.31:21, username:remote, password:123456789
I am trying to draw a list of all contacts saved in device. Everything is fine but when I select all contacts, I get only those contacts which are drawn on the screen. In other words, list drawing only those contacts which are visible on screen. To get the remaining contacts I have to scroll the list.
Here is my code:
public class CheckboxListField extends VerticalFieldManager implements ListFieldCallback, FieldChangeListener {
private static Vector selectedContacts ;
private ChecklistData[] mListData = new ChecklistData[] {};
private ListField mListField;
private static Vector mContacts;
private ContactList contactList;
private Enumeration allContacts;
private SendEmail sendEmail;
private boolean isChecked=false;
private BlackBerryContact contactItem;
private VerticalFieldManager _mainVFM = new VerticalFieldManager();
private int i;
private int j=0;
private String emails="";
private ButtonField _inviteButton;
private HorizontalFieldManager selectAllHFM;
private CustomButtonField selectAllButton;
private Bitmap _uncheckBmp;
private Bitmap _checkBmp;
private LabelField selectAllLabel;
private CheckboxField selectAllCheckBox;
private VerticalFieldManager contactListVFM;
private boolean listItemChecked=false;
private StringBuffer rowString;
private boolean getCBoxStatus;
// A class to hold the Strings in the CheckBox and it's checkbox state
// (checked or unchecked).
private class ChecklistData {
private String _stringVal;
private boolean _checked;
private String _telNumber;
ChecklistData(String stringVal, boolean checked) {
_stringVal = stringVal;
_checked = checked;
//_telNumber = telNumber;
}
// Get/set methods.
private String getStringVal() {
return _stringVal;
}
private boolean isChecked() {
return _checked;
}
// Toggle the checked status.
public void toggleChecked() {
_checked = !_checked;
}
}
public CheckboxListField() {
_mainVFM.add(createContactList(isChecked));
add(_mainVFM);
}
public VerticalFieldManager createContactList(boolean checked){
isChecked = checked;
selectedContacts = new Vector();
//INVITE BUTTON
contactListVFM = new VerticalFieldManager();
_inviteButton=new ButtonField("Invite Friend");
_inviteButton.setChangeListener(this);
_inviteButton.setMargin(2,0,10,0);
//SELECT ALL CHECKBOX
selectAllHFM = new HorizontalFieldManager();
_uncheckBmp = Bitmap.getBitmapResource("Uncheck.png");
_checkBmp = Bitmap.getBitmapResource("checked.png");
selectAllButton = new CustomButtonField(29, "", _uncheckBmp, _checkBmp, ButtonField.CONSUME_CLICK);
selectAllButton.setChangeListener(this);
selectAllButton.setMargin(5,5,5,5);
selectAllCheckBox = new CheckboxField("Select All", isChecked){
protected boolean navigationClick(int status,
int time) {
selectedContacts = new Vector();
emails = "";
boolean getCBoxStatus = selectAllCheckBox.getChecked();
if(listItemChecked == false){
if(_mainVFM.getFieldCount()!= 0){
_mainVFM.deleteAll();
_mainVFM.add(createContactList(getCBoxStatus));
}
}
return true;
}
};
selectAllCheckBox.setChangeListener(this);
selectAllLabel = new LabelField("Select All");
selectAllLabel.setMargin(5,5,5,5);
selectAllHFM.add(selectAllCheckBox);
//selectAllHFM.add(selectAllLabel);
// toggle list field item on navigation click
mListField = new ListField() {
protected boolean navigationClick(int status,
int time) {
toggleItem();
return true;
};
};
// set two line row height
//mListField.setRowHeight(getFont().getHeight() * 2);
mListField.setCallback(this);
//contactListVFM.add(new NullField(NullField.FOCUSABLE));
contactListVFM.add(_inviteButton);
contactListVFM.add(selectAllHFM);
contactListVFM.add(new SeparatorField());
contactListVFM.add(mListField);
//LOAD CONTACTS
// load contacts in separate thread
loadContacts.run();
return contactListVFM;
}
protected Runnable loadContacts = new Runnable() {
public void run() {
reloadContactList();
// fill list field control in UI event thread
UiApplication.getUiApplication().invokeLater(
fillList);
}
};
protected Runnable fillList = new Runnable() {
public void run() {
int size = mContacts.size();
mListData = new ChecklistData[size];
for (int i =0; i < mContacts.size() ; i++) {
contactItem = (BlackBerryContact) mContacts
.elementAt(i);
String displayName = getDisplayName(contactItem);
// String telContact = getContact(item);
mListData[i] = new ChecklistData(
displayName, isChecked);
mListField.invalidate(i);
System.out.println(">>>>>>>>>"+mListData[i]);
}
mListField.setSize(size);
//invalidate();
}
};
protected void toggleItem() {
listItemChecked = true ;
selectAllCheckBox.setChecked(false);
listItemChecked =false ;
// Get the index of the selected row.
int index = mListField.getSelectedIndex();
System.out.println("..............."+index);
if (index != -1) {
// Get the ChecklistData for this row.
ChecklistData data = mListData[index];
// Toggle its status.
data.toggleChecked();
mListField.invalidate(index);
}
}
private boolean reloadContactList() {
try {
contactList = (ContactList) PIM
.getInstance()
.openPIMList(PIM.CONTACT_LIST,
PIM.READ_ONLY);
allContacts = contactList.items();
mContacts = enumToVector(allContacts);
mListField.setSize(mContacts.size());
System.out.println(",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,>>>>>>>>>>"+mListField.getSize());
return true;
} catch (PIMException e) {
return false;
}
}
// Convert the list of contacts from an Enumeration to a Vector
private Vector enumToVector(Enumeration contactEnum) {
Vector v = new Vector();
if (contactEnum == null)
return v;
while (contactEnum.hasMoreElements()){
Contact contact = (Contact) allContacts.nextElement();
if(contactList.isSupportedField(Contact.EMAIL)&& (contact.countValues(Contact.EMAIL) > 0)) {
String emailID=contact.getString(Contact.EMAIL, 0);
if(emailID.length() !=0 && emailID != null ){
v.addElement(contact);
}
}
}
return v;
}
public void drawListRow(ListField list,
Graphics graphics, int index, int y, int w) {
rowString = new StringBuffer();
Object obj = this.get(list, index);
if (list.getSelectedIndex() != index) {
graphics.setBackgroundColor(index % 2 == 0 ||index==0 ? Color.WHITE
: Color.LIGHTGRAY);
graphics.clear();
//list.setFocus();
}
BlackBerryContact contact = (BlackBerryContact) mContacts
.elementAt(index);
String email= contact.getString(Contact.EMAIL, 0);
int vecIndex = selectedContacts.indexOf(email);
if (obj != null) {
ChecklistData currentRow = (ChecklistData) obj;
if (currentRow.isChecked()) {
if(vecIndex == -1){
selectedContacts.addElement(email);
}
rowString
.append(Characters.BALLOT_BOX_WITH_CHECK);
} else {
selectedContacts.removeElement(email);
rowString.append(Characters.BALLOT_BOX);
}
// Append a couple spaces and the row's text.
rowString.append(Characters.SPACE);
rowString.append(Characters.SPACE);
rowString.append(currentRow.getStringVal());
// Draw the text.
}
graphics.drawText(rowString.toString(), 0, y,
0, w);
}
public static String getDisplayName(Contact contact) {
if (contact == null) {
return null;
}
String displayName = null;
// First, see if there is a meaningful name set for the contact.
if (contact.countValues(Contact.NAME) > 0) {
final String[] name = contact.getStringArray(
Contact.NAME, 0);
final String firstName = name[Contact.NAME_GIVEN];
final String lastName = name[Contact.NAME_FAMILY];
if (firstName != null && lastName != null) {
displayName = firstName + " " + lastName;
} else if (firstName != null) {
displayName = firstName;
} else if (lastName != null) {
displayName = lastName;
}
if (displayName != null) {
final String namePrefix = name[Contact.NAME_PREFIX];
if (namePrefix != null) {
displayName = namePrefix + " "
+ displayName;
}
return displayName;
}
}
return displayName;
}
// Returns the object at the specified index.
public Object get(ListField list, int index) {
Object result = null;
if (mListData.length > index) {
result = mListData[index];
}
System.out.println(",,,,,,,,,,,,,,,,,,,,,,,"+mListData.length);
return result;
}
// Returns the first occurrence of the given String,
// beginning the search at index, and testing for
// equality using the equals method.
public int indexOfList(ListField list, String p, int s) {
return -1;
}
// Returns the screen width so the list uses the entire screen width.
public int getPreferredWidth(ListField list) {
return Graphics.getScreenWidth();
// return Display.getWidth();
}
public void fieldChanged(Field field, int context) {
if(field==_inviteButton){
for(int n=0 ; n<selectedContacts.size() ; n++){
emails= emails + selectedContacts.elementAt(n)+",";
}
//}
String mailBody =": "+Jxa.loginUserName+" invited you on NaijaPings app. Please download NaijaPings Android app from here "+"http://appworld.blackberry.com/webstore/content/77264/?lang=en" ;
sendEmail=new SendEmail(mailBody);
sendEmail.Email(emails,Constant.emailSubject);
emails ="" ;
selectedContacts.removeAllElements();
}else if(field == selectAllCheckBox){
selectedContacts = new Vector();
emails = "";
getCBoxStatus = selectAllCheckBox.getChecked();
//selectedContacts.removeAllElements();
if(listItemChecked == false){
if(_mainVFM.getFieldCount()!= 0){
_mainVFM.deleteAll();
_mainVFM.add(createContactList(getCBoxStatus));
}
}
}
}
}
Here ,in drawListRow() , get() method is called only that many times that is number of contacts are visible on the screen. For remaining contact to add, I have to scroll the list.
In drawListRow() method I am adding those contacts into selectedContacts vector and than using those vector to get contact to send a mail. Contacts will be added only when particular list item will be drawn.
So, how I can get all selected contact without scrolling the list?
This is similar to the problem you had in one of your other recent questions. The problem is that drawListRow() is a callback designed to let you draw the rows that need drawing. It's not meant to do anything else, like assembling a list of contacts to email.
The BlackBerry OS tries to be efficient, so it will only ask you to drawListRow() for the rows that are actually visible to the user (on screen). Anything more would be wasteful.
So, if you want to assemble a list of all selected rows, you should do it somewhere else, not in drawListRow().
It looks to me like you can build a list of all currently selected rows by using this code, wherever you want:
public Vector getSelectedContacts() {
selectedContacts.removeAllElements();
for (int i = 0; i < mListData.length; i++) {
Object obj = mListData[i];
if (obj != null) {
BlackBerryContact contact = (BlackBerryContact) mContacts.elementAt(i);
String email = contact.getString(Contact.EMAIL, 0);
int vecIndex = selectedContacts.indexOf(email);
ChecklistData currentRow = (ChecklistData) obj;
if (currentRow.isChecked()) {
if(vecIndex == -1){
selectedContacts.addElement(email);
}
} else {
// this line is probably not actually needed, since we
// call removeAllElements() at the start of this method
selectedContacts.removeElement(email);
}
}
}
return selectedContacts;
}
in my application i have a Custom text box with BasicEditField.FILTER_NUMERIC. When the user enter the value in the field the comma should be added to the Currency format .
EX:1,234,567,8.... like this.
In my code i tried like this.
protected boolean keyUp(int keycode, int time) {
String entireText = getText();
if (!entireText.equals(new String(""))) {
double val = Double.parseDouble(entireText);
String txt = Utile.formatNumber(val, 3, ",");// this will give the //comma separation format
setText(txt);// set the value in the text box
}
return super.keyUp(keycode, time);
}
it will give the correct number format... when i set the value in the text box it will through the IllegalArgumentException. I know BasicEditField.FILTER_NUMERIC will not allow the charector like comma(,)..
How can i achieve this?
I tried this way and it works fine...
public class MyTextfilter extends TextFilter {
private static TextFilter _tf = TextFilter.get(TextFilter.REAL_NUMERIC);
public char convert(char character, int status) {
char c = 0;
c = _tf.convert(character, status);
if (c != 0) {
return c;
}
return 0;
}
public boolean validate(char character) {
if (character == Characters.COMMA) {
return true;
}
boolean b = _tf.validate(character);
if (b) {
return true;
}
return false;
}
}
and call like this
editField.setFilter(new MyTextfilter());