自定义列表字段单击事件
Nir*_*ari 4 java blackberry listfield blackberry-jde
即时编写一个应用程序,我已经创建了自定义列表字段来显示列表视图.我的CustomListField包含一行中的一个图像和文本.im gettiing字段更改监听器点击listfield行但我想把fieldchange监听器放在图像上..任何人都可以告诉我我该怎么做.
这是我的代码.
public class CustomListField extends ListField implements ListFieldCallback {
private Vector _listData;
private int _MAX_ROW_HEIGHT = 60;
public CustomListField(Vector data) {
_listData = data;
setSize(_listData.size());
setSearchable(true);
setCallback(this);
setRowHeight(_MAX_ROW_HEIGHT);
}
protected void drawFocus(Graphics graphics, boolean on) {
XYRect rect = new XYRect();
graphics.setGlobalAlpha(150);
graphics.setColor(Color.BLUE);
getFocusRect(rect);
drawHighlightRegion(graphics, HIGHLIGHT_FOCUS, true, rect.x, rect.y, rect.width, rect.height);
}
public int moveFocus(int amount, int status, int time) {
this.invalidate(this.getSelectedIndex());
return super.moveFocus(amount, status, time);
}
public void onFocus(int direction) {
super.onFocus(direction);
}
protected void onUnFocus() {
this.invalidate(this.getSelectedIndex());
}
public void refresh() {
this.getManager().invalidate();
}
public void drawListRow(ListField listField, Graphics graphics, int index, int y, int w) {
listField.setBackground(BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("listing_bg.png")));
ListRander listRander = (ListRander) _listData.elementAt(index);
graphics.setGlobalAlpha(255);
graphics.setFont(Font.getDefault().getFontFamily().getFont(Font.PLAIN, 24));
final int margin = 5;
final Bitmap thumb = listRander.getListThumb();
final String listHeading = listRander.getListTitle();
final Bitmap nevBar = listRander.getNavBar();
// list border
graphics.setColor(Color.GRAY);
graphics.drawRect(0, y, w, _MAX_ROW_HEIGHT);
// thumbnail border & thumbnail image
graphics.setColor(Color.BLACK);
// graphics.drawRoundRect(margin-2, y+margin-2,thumb.getWidth()+2, thumb.getHeight()+2, 5, 5);
graphics.drawBitmap(margin, y + margin, thumb.getWidth(), thumb.getHeight(), thumb, 0, 0);
// drawing texts
// graphics.setFont(Font.BOLD);
graphics.drawText(listHeading, margin + thumb.getWidth(), y + margin);
graphics.setColor(Color.GRAY);
// graphics.setFont(Font.smallFont); // graphics.drawText(listDesc, 2*margin+thumb.getWidth(), y+ margin+20); // //
// graphics.drawText(listDesc2, 2*margin+thumb.getWidth(), y+ margin+32);
// draw navigation button
final int navBarPosY = y + (_MAX_ROW_HEIGHT / 2 - nevBar.getHeight() / 2);
final int navBarPosX = Graphics.getScreenWidth() - nevBar.getWidth() + margin;
graphics.drawBitmap(navBarPosX, navBarPosY, nevBar.getWidth(), nevBar.getHeight(), nevBar, 0, 0);
}
public Object get(ListField listField, int index) {
String rowString = (String) _listData.elementAt(index);
return rowString;
}
public int indexOfList(ListField listField, String prefix, int start) {
for (Enumeration e = _listData.elements(); e.hasMoreElements();) {
String rowString = (String) e.nextElement();
if (rowString.startsWith(prefix)) {
return _listData.indexOf(rowString);
}
}
return 0;
}
public int getPreferredWidth(ListField listField) {
return 3 * listField.getRowHeight();
}
/*
protected boolean trackwheelClick(int status, int time) {
invalidate(getSelectedIndex());
Dialog.alert(" U have selected :" + getSelectedIndex());
return super.trackwheelClick(status, time);
}
*/
}
我想把clickClickner放在listfield行的星形图像上
以下是输出的代码.
我在过去的项目中做了类似的事情:
背景
正如Arhimed在他的回答中所说的那样,正如你在黑莓论坛上可以看到的那样,你不可能拥有完整的Field对象ListField.ListField行的内容只是drawListRow()作为文本和位图等直接绘制.内容不是Field实例,因此不可聚焦.
所以,我所做的是替换ListField为子类Manager.最初,我用了一个VerticalFieldManager,但我遇到了问题.我也看到了很多关于堆栈溢出的问题,人们在子类中VerticalFieldManager,只定制一个小行为,一切都开始破坏.在我看来,VerticalFieldManager如果你接受它的正常行为,那么效果很好,如果你需要更多东西,只需Manager直接延伸.执行垂直堆叠行的布局非常简单.
然后我将每一行都设置为自己的Manager,并实现自定义布局,sublayout()将行Field放在我想要的位置.然后我也可以使行可聚焦,然后行上的位图/按钮可以单独聚焦(就像你的星星一样).单击该行会调用一个操作,单击该星会调用另一个操作.
但是,我会注意到,在我的应用程序中,性能不是问题,因为我只有10-20行.此外,我确实需要修改我的代码以匹配您的示例,因此请仔细考虑此代码.但是,我确实将它构建到一个应用程序中,因此只要我的假设和您的描述都有效,它就应该可以正常运行.
履行
首先,我不清楚你ListRander是什么(你没有显示该代码).然而,在我的代码,我需要一个数据类包含了大约细节一个排.它看起来就像你使用的那样ListRander,所以我使用的是:
public class ListRander {
private String _title;
private Bitmap _thumb;
public ListRander(String title, Bitmap thumb) {
_title = title;
_thumb = thumb;
}
public String getTitle() {
return _title;
}
public Bitmap getThumb() {
return _thumb;
}
}
然后,我用自己的CustomListField课程替换了你的课程:
public class CustomListField extends Manager implements FocusChangeListener {
private int _MAX_ROW_HEIGHT = 60;
private boolean _searchable = false;
private Vector _listData;
private FieldChangeListener _fieldListener;
public CustomListField(Vector data) {
super(FOCUSABLE | VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
setSearchable(true);
setEditable(false);
setListData(data);
}
public void setChangeListener(FieldChangeListener listener) {
// we need to save this listener, because we set it to listen to all new rows
_fieldListener = listener;
int numFields = getFieldCount();
for (int f = 0; f < numFields; f++) {
getField(f).setChangeListener(listener);
}
super.setChangeListener(listener);
}
public int getRowHeight() {
return _MAX_ROW_HEIGHT;
}
public void setSearchable(boolean searchable) {
_searchable = searchable;
}
public int getSelectedIndex() {
return getFieldWithFocusIndex(); // TODO??
}
public Object get(int index) {
return _listData.elementAt(index);
}
public int indexOfList(String prefix, int start) {
if (start >= _listData.size() || !_searchable) {
return -1;
} else {
int result = getSelectedIndex(); // the default result if we find no matches
for (Enumeration e = _listData.elements(); e.hasMoreElements(); ) {
String rowString = (String) e.nextElement();
if (rowString.startsWith(prefix)) {
return _listData.indexOf(rowString);
}
}
return result;
}
}
protected boolean navigationClick(int status, int time) {
CustomListRow focus = (CustomListRow) getFieldWithFocus();
if (focus != null) {
// see if the row wants to process this click
if (!focus.navigationClick(status, time)) {
// let our FieldChangeListener know that this row has been clicked
fieldChangeNotify(getFieldWithFocusIndex());
}
return true;
} else {
return false;
}
}
protected void sublayout(int width, int height) {
int w = Math.min(width, getPreferredWidth());
int h = Math.min(height, getPreferredHeight());
int rowHeight = getRowHeight();
int numRows = getFieldCount();
setExtent(w, h);
setVirtualExtent(w, rowHeight * numRows);
for (int i = 0; i < numRows; i++) {
Field f = getField(i);
setPositionChild(f, 0, rowHeight * i);
layoutChild(f, w, rowHeight);
}
}
public int getPreferredWidth() {
return Display.getWidth();
}
public int getPreferredHeight() {
return Display.getHeight();
}
public void setListData(Vector listData) {
_listData = listData;
if (listData != null) {
int listSize = listData.size();
int numRows = getFieldCount();
for (int s = 0; s < listSize; s++) {
if (s < numRows) {
// we can reuse existing CustomListRows
CustomListRow row = (CustomListRow) getField(s);
row.setData((ListRander) listData.elementAt(s));
} else {
CustomListRow row = new CustomListRow((ListRander) listData.elementAt(s));
row.setChangeListener(_fieldListener);
row.setFocusListener(this);
add(row);
}
}
if (listSize < numRows) {
// delete the excess rows
deleteRange(listSize, numRows - listSize);
}
} else {
deleteAll();
}
invalidate();
}
public void focusChanged(Field field, int eventType) {
// we handle scrolling here, when focus changes between rows
if (eventType == FOCUS_GAINED) {
if (field.getTop() < getVerticalScroll()) {
// field is off the top of the screen, so scroll up
setVerticalScroll(field.getTop());
} else if (field.getTop() >= getVerticalScroll() + getVisibleHeight()) {
// field is off the bottom of the screen, so scroll down
setVerticalScroll(field.getTop() - getVisibleHeight() + getRowHeight());
}
}
}
}
最后,我的CustomListRow班级代表一行:
public class CustomListRow extends Manager implements FieldChangeListener {
private static final int _MAX_ROW_HEIGHT = 60;
private ListRander _data;
private BitmapField _thumb;
private LabelField _title;
private FocusableBitmapField _star;
private static final Bitmap _starImg = Bitmap.getBitmapResource("star.png");
private static final Bitmap _bgImg = Bitmap.getBitmapResource("listing_bg.png");
private SeparatorField _separator;
private int _fontColor = Color.BLACK;
private boolean _highlighted = false;
private int _width;
// subclass exists to expose focus methods (make public)
private class FocusableBitmapField extends BitmapField {
public FocusableBitmapField() {
super(_starImg, BitmapField.FOCUSABLE | BitmapField.EDITABLE);
}
public void onFocus(int direction) {
super.onFocus(direction);
}
public void onUnfocus() {
super.onUnfocus();
}
}
public CustomListRow(ListRander data) {
super(Field.FOCUSABLE | Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR);
setBackground(BackgroundFactory.createBitmapBackground(_bgImg));
_width = Display.getWidth();
long labelStyle = (DrawStyle.LEFT | DrawStyle.TOP | DrawStyle.ELLIPSIS);
_title = new LabelField("", labelStyle) { // custom anonymous class to change font color
protected void paint(Graphics g) {
int c = g.getColor();
g.setColor(_fontColor);
super.paint(g);
g.setColor(c);
}
};
_title.setFont(Font.getDefault().getFontFamily().getFont(Font.PLAIN, 24));
_thumb = new BitmapField();
_star = new FocusableBitmapField();
_star.setChangeListener(this);
_separator = new SeparatorField() { // custom anonymous class to change separator color
protected void paint(Graphics g) {
int c = g.getColor();
g.setColor(Color.GRAY);
super.paint(g);
g.setColor(c);
}
};
setData(data);
add(_thumb);
add(_title);
add(_star);
add(_separator);
}
public ListRander getData() {
return _data;
}
public void setData(ListRander value) {
if (value != _data) {
_data = value;
_title.setText(value.getTitle());
_thumb.setBitmap(value.getThumb());
}
}
private void onStarClicked() {
Dialog.alert("Star has been clicked or tapped!");
}
private void onRowClicked() {
Dialog.alert("Row has been clicked or tapped!");
}
public void fieldChanged(Field field, int context) {
if (field == _star) {
onStarClicked();
}
}
public boolean navigationClick(int status, int time) {
if (_star.isFocus()) {
onStarClicked();
return true;
} /* else {
onRowClicked();
return true;
} */
return false; // we will not consume this event
}
protected void highlight(boolean onRow) {
_fontColor = onRow ? Color.WHITE : Color.BLACK; // change font color for contrast
_highlighted = onRow;
invalidate();
}
protected void onFocus(int direction) {
// called when focus first transfers to this row, from another Field
if (direction == 1) {
// coming from top to bottom, we highlight the row first, not the star
highlight(true);
} else if (direction == -1) {
// coming from bottom to top, we highlight the star button first, not the row
_star.onFocus(direction);
highlight(false);
}
}
protected void onUnfocus() {
// remove highlighting of the row, if any
highlight(false);
super.onUnfocus();
}
protected int moveFocus(int amount, int status, int time) {
// called when this row already has focus (either on row, or star button)
if (amount > 0) {
// moving top to bottom
if (!_star.isFocus()) {
// we were on the row, now move to the star button
_star.onFocus(1);
highlight(false);
amount--; // consume one unit of movement
}
} else {
// moving from bottom to top
if (_star.isFocus()) {
// we were on the star button, now move back over to the row
_star.onUnfocus();
highlight(true);
amount++; // consume one unit of movement
}
}
return amount;
}
protected boolean touchEvent(net.rim.device.api.ui.TouchEvent event) {
// We take action when the user completes a click (a.k.a. unclick)
int eventCode = event.getEvent();
if ((eventCode == TouchEvent.UNCLICK) || (eventCode == TouchEvent.DOWN)) {
// Get the touch location, within this Manager
int x = event.getX(1);
int y = event.getY(1);
if ((x >= 0) && (y >= 0) && (x < _width) && (y < _MAX_ROW_HEIGHT)) {
int field = getFieldAtLocation(x, y);
if ((field >= 0) && (getField(field) == _star)) {
// Let event propagate to (star) button field
return super.touchEvent(event);
} else {
if (eventCode == TouchEvent.UNCLICK) {
// A completed click anywhere else in this row should popup details for this selection
fieldChangeNotify(1);
onRowClicked();
} else {
// This is just a soft touch (TouchEvent.DOWN), without full click
setFocus();
}
// Consume the event
return true;
}
}
}
// Event wasn't for us, let superclass handle in default manner
return super.touchEvent(event);
}
protected void sublayout(int width, int height) {
height = Math.min(getPreferredHeight(), height);
setExtent(_width, height);
final int margin = 5;
int thumbWidth = _thumb.getPreferredWidth();
layoutChild(_thumb, thumbWidth, _thumb.getPreferredHeight());
setPositionChild(_thumb, margin, margin);
int starWidth = _star.getPreferredWidth();
int starHeight = _star.getPreferredHeight();
layoutChild(_star, starWidth, starHeight);
setPositionChild(_star, width - starWidth - margin, (height - starHeight) / 2);
// this assumes you want margin between all fields, and edges
layoutChild(_title, width - thumbWidth - starWidth - 4 * margin, _title.getPreferredHeight());
setPositionChild(_title, margin + thumbWidth /* + margin */, margin); // TODO?
}
protected void paintBackground(Graphics g) {
super.paintBackground(g);
if (_highlighted) {
// you can't override drawFocus() for a Manager, so we'll handle that here:
int oldColor = g.getColor();
int oldAlpha = g.getGlobalAlpha();
XYRect rect = new XYRect();
g.setGlobalAlpha(150);
g.setColor(Color.BLUE);
getFocusRect(rect);
drawHighlightRegion(g, HIGHLIGHT_FOCUS, true, rect.x, rect.y, rect.width, rect.height);
g.setGlobalAlpha(oldAlpha);
g.setColor(oldColor);
}
}
public int getPreferredWidth() {
return _width;
}
public int getPreferredHeight() {
return _MAX_ROW_HEIGHT;
}
}
用法
这是您可以使用整个列表字段(可能在Screen类中):
public class ListScreen extends MainScreen implements FieldChangeListener {
public ListScreen() {
try {
Vector data = new Vector();
Bitmap icon = Bitmap.getBitmapResource("list_icon.png");
for (int i = 0; i < 15; i++) {
ListRander lr = new ListRander("Product Name " + i, icon);
data.addElement(lr);
}
CustomListField list = new CustomListField(data);
add(list);
list.setChangeListener(this);
} catch (Exception e) {
e.printStackTrace();
}
}
public void fieldChanged(Field field, int context) {
if (field instanceof CustomListRow) {
CustomListRow row = (CustomListRow) field;
Dialog.alert(row.getData().getTitle() + " was selected!");
}
}
}
在我的应用程序中,它CustomListRow本身有意义处理相当于您的星形点击.但是,对我来说,以这种方式处理行单击是没有意义的.所以,我让你设置一个的本身而言,选择任何一行时叫回.请参阅我的屏幕类中的上述示例.如果你要处理的行点击里面的类也一样,这很好.我在那里制定了一种方法.在代码中搜索已注释掉的位置,并且可以重新激活,即方法().FieldChangeListenerCustomListFieldCustomListRowonRowClicked()onRowClicked()
问题
- 我的应用程序不需要列表搜索.我列出了一个示例实现,就像
ListField有.但是,我没有测试它.如果你需要,这是你的工作.我刚开始介绍CustomListField实现(参见参考资料indexOfList()). - 我没看到你的"导航栏"是什么.条形图通常是全角项目,如状态栏或工具栏.我的截图中没有看到类似的内容.导航项可能是每行右侧的一个小箭头,以显示细节.但是,我在你的截图中也没有看到.所以,我忽略了那段代码.如果你需要一个导航栏,你显然知道它应该是什么,并可以将其添加到我上面的代码中.
- 我不知道你是否只是将星形作为行背景图像的一部分添加,或者你是否有一个单独的图像.我添加了一个单独的star.png来代表明星.我会假设点击星星填充它,或突出显示它或其他东西.但是,你没有描述这个问题,所以我认为你可以解决这个问题.如果您需要一个自定义字段来表示星形,可以选择和未选择的图像,只需将其作为新问题发布.
- 你有一些代码似乎试图将行宽设置为行高的3倍,但这与你的屏幕截图不匹配.无论如何,大多数列表都是全屏宽度.所以,我删除了该代码.我的
CustomListRow类实现getPreferredWidth()并请求全屏宽度.如果你愿意改变.
与Android不同ListView,BB的ListField设计不包含列表项内的可聚焦/可点击字段.因此,任何解决此问题的尝试都会产生一些负面影响.
一个相对容易/快速的解决方法是切换到VerticalFieldManager(检查其他堆栈溢出问题).但如果列表太长(我相信超过几百个),你就有可能"吃掉"太多的记忆.
如果该应用程序仅适用于触摸屏,那么您可以尝试使用ListField+对触摸事件坐标进行一些手动跟踪.因此,当您检测到列表字段单击时(以通常的方式执行),您可以检查触摸坐标是否对应于星形图像区域(至少在X轴上).我不打算发明/提供实现,而只是提出一个想法.