com.maryanovsky.gwtutils.client
Class UiUtils

java.lang.Object
  com.maryanovsky.gwtutils.client.UiUtils

public class UiUtils
extends Object

A utility class for UI related functionality.

Author:

Maryanovsky Alexander

Field Summary

static com.maryanovsky.gwtutils.client.UiUtils.Delegate	LTR The delegate for left-to-right languages.
static com.maryanovsky.gwtutils.client.UiUtils.Delegate	RTL The delegate for right-to-left languages.

Constructor Summary

UiUtils()

Method Summary

static void	addDependentStyleName(Widget widget, String styleSuffix) Adds a dependent style name to the specified widget.
static void	addDialogButtons(HorizontalPanel panel, Widget[] buttons) Adds the specified dialog buttons to the specified panel.
static void	addFullSize(Panel panel, Widget widget) Adds the specified widget to the specified absolute panel and makes it occupy the panel fully.
static void	addInCorner(Panel panel, Widget widget, Alignment corner, SizeView offset) Adds the specified widget to the specified corner of the specified panel with the specified offset from the borders.
static void	addWidgets(HorizontalPanel panel, Widget[] widgets) Adds the specified widgets to the specified horizontal panel in reading order.
static void	applyPngHack(Image image, String url, Size size) Applies the IE PNG hack to the specified image.
static void	cancelCurrentEvent() Cancels processing of the current event by cancalling bubble and preventing the default action on event from occurring.
static void	disableContextMenu(Element element) Disables the browser context menu for the specified element (and enables right-click detection).
static void	disableDragging(Object dragTracker) Makes the specified widget un-draggable, after it was made draggable with makeDraggable(Widget, SourcesMouseEvents, DragAction).
static void	extraImageCellHeightWorkaround(Element tdElement) Fixes a strange problem with an image being placed in a table cell.
static void	extraImageCellHeightWorkaround(Widget panel) Fixes the problem described by extraImageCellHeightWorkaround(Element) for every TD element of the specified panel.
static void	fillRow(HTMLTable table, int row, int height) Fills the specified row of a table with vertical struts of the specified size.
static void	findElementsByTagName(Element parent, String tagName, List list) Finds the children of the specified element whose tag name is the specified one, and adds them to the specified list.
static Widget	getHorizontalStrut(int width) Creates a horizontal spacer of the specified width.
static HasHorizontalAlignment.HorizontalAlignmentConstant	getLeadingAlignment() Returns the alignment constant corresponding to the beginning of the line in reading order.
static String	getPngHackedImageHtml(String url, Size size) Returns the HTML for an image at the specified URL with the PNG hack applied to it.
static String	getPrimaryStyleName(String fullStyleName) Returns the "primary" style name based on the specified full style name.
static String	getPrimaryStyleName(Widget widget) Returns the "primary" style name of the specified widget.
static Widget	getRelatedHorizontalStrut() Returns a horizontal spacer of with the size of the preferred distance between related elements.
static Widget	getRelatedVerticalStrut() Returns a vertical spacer of with the size of the preferred distance between related elements.
static Widget	getRigidArea(int width, int height) Creates a spacer of the specified dimensions.
static String	getTagName(Element element) Returns the tag name of the specified element.
static Point	getTopLeft(Widget widget) Returns the top-left location of an absolutely positioned widget from its "top" and "left" style attributes.
static HasHorizontalAlignment.HorizontalAlignmentConstant	getTrailingAlignment() Returns the alignment constant corresponding to the end of the line in reading order.
static Widget	getUnrelatedHorizontalStrut() Returns a horizontal spacer of with the size of the preferred distance between unrelated elements.
static Widget	getUnrelatedVerticalStrut() Returns a vertical spacer of with the size of the preferred distance between unrelated elements.
static Widget	getVerticalStrut(int height) Creates a vertical spacer of the specified height.
static Object	makeDraggable(Widget widget, SourcesMouseEvents dragHandle, DragAction dragAction) Makes the specified widget draggable via the specified drag handle.
static Label	makeLabelFor(String text) Creates a label to be a label for some other element.
static HTMLTable	prepareLayoutTable(HTMLTable table) Prepares the specified table to be a layout table by clearing its cell padding, spacing and border.
static void	setAbsoluteBounds(Widget widget, int left, int top, int width, int height) Sets the bounds of the specified widget and its "position" style attribute to "absolute".
static void	setAbsoluteFullSize(Widget widget) Sets the specified widget's position attribute to "absolute", its top and left attributes to "0px" and its width and height attributes to "100%".
static void	setBounds(Widget widget, int left, int top, int width, int height) Sets the "left", "top", "width" and "height" attributes of the widget to the specified values, in pixels.
static void	setContainingSize(AbsolutePanel panel) Sets the bounds of the specified panel so that all of its widgets are within them (obviously, except those placed at negative coordinates).
static void	setDataDirection(Widget widget) Sets the direction of the specified widget to LTR.
static void	setDelegate(com.maryanovsky.gwtutils.client.UiUtils.Delegate delegate) Sets the current delegate.
static void	setElementId(Widget widget, String id) Sets the id attribute of the specified widget's DOM element to the specified value.
static void	setFullSize(Widget widget) Sets the specified widget's top and left attributes to "0px" and its width and height attributes to "100%".
static void	setGrabbingCursor(Widget widget) Sets the "grabbing" cursor on the specified widget, if supported.
static void	setGrabbingCursorUrl(String url) Sets the grabbing cursor to the specified URL.
static void	setGrabCursor(Widget widget) Sets the "grab" cursor on the specified widget, if supported.
static void	setGrabCursorUrl(String url) Sets the grab cursor to the specified URL.
static void	setGridRow(Grid grid, int row, Widget[] widgets) Puts the specified widgets into the specified row in the grid, in language order.
static void	setGridRow(Grid grid, int row, Widget[] widgets, HasVerticalAlignment.VerticalAlignmentConstant[] vAlignments, HasHorizontalAlignment.HorizontalAlignmentConstant[] hAlignments) Puts the specified widgets into the specified row in the grid, in language order.
static void	setLeadingMargin(Widget widget, int size) Sets the margin leading the element, in the reading direction (left when in LTR, right when in RTL mode).
static void	setOpacity(Widget widget, double opacity) Sets the opacity of the specified widget to the specified value, where 0 stands for completely transparent and 1 for completely opaque.
static void	setTextDirection(Widget widget) Sets the direction of the specified widget to the direction of the application's language.
static void	setTopLeft(Widget widget, int x, int y) Sets the widget's position via the "top" and "left" style attributes.
static void	setTopLeft(Widget widget, PointView point) Sets the widget's position via the "top" and "left" style attributes.
static void	setTrailingMargin(Widget widget, int size) Sets the margin trailing the element, in the reading direction (right when in LTR, left when in RTL mode).
static void	setVisible(Widget widget, boolean isVisible) Sets the visibility of the specified widget.
static void	setVisualWidth(Widget widget, int width) Sets the width of the specified widget so that its visual width is as specified.
static void	setVisualWidth(Widget widget, Object elementType, int width) Sets the width of the specified widget so that its visual width is as specified.
static void	setZOrder(Widget[] widgets) Sets the z-indices of the specified widgets to their indices in the specified array, making widgets with greater indices appear on top of widgets with smaller indices.
static void	stopTrackingResizes(Object resizeTracker) Stops tracking size changes for some widget.
static Object	trackResizes(Widget widget, ChangeListener listener) Attempts to track changes in the size of the specified widget and notify the specified change listener.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LTR

public static final com.maryanovsky.gwtutils.client.UiUtils.Delegate LTR

The delegate for left-to-right languages.

RTL

public static final com.maryanovsky.gwtutils.client.UiUtils.Delegate RTL

The delegate for right-to-left languages.

Constructor Detail

UiUtils

public UiUtils()

Method Detail

setDelegate

public static void setDelegate(com.maryanovsky.gwtutils.client.UiUtils.Delegate delegate)

Sets the current delegate. Possible values are LTR and RTL.

makeLabelFor

public static Label makeLabelFor(String text)

Creates a label to be a label for some other element.

setLeadingMargin

public static void setLeadingMargin(Widget widget,
                                    int size)

Sets the margin leading the element, in the reading direction (left when in LTR, right when in RTL mode).

setTrailingMargin

public static void setTrailingMargin(Widget widget,
                                     int size)

Sets the margin trailing the element, in the reading direction (right when in LTR, left when in RTL mode).

setGridRow

public static void setGridRow(Grid grid,
                              int row,
                              Widget[] widgets)

Puts the specified widgets into the specified row in the grid, in language order.

setGridRow

public static void setGridRow(Grid grid,
                              int row,
                              Widget[] widgets,
                              HasVerticalAlignment.VerticalAlignmentConstant[] vAlignments,
                              HasHorizontalAlignment.HorizontalAlignmentConstant[] hAlignments)

Puts the specified widgets into the specified row in the grid, in language order. Additionally, the corresponding cells are set to the specified alignments (when the alignment values are non-null).

addWidgets

public static void addWidgets(HorizontalPanel panel,
                              Widget[] widgets)

Adds the specified widgets to the specified horizontal panel in reading order.

addDialogButtons

public static void addDialogButtons(HorizontalPanel panel,
                                    Widget[] buttons)

Adds the specified dialog buttons to the specified panel. The order of the arguments should be consistent with MS Windows standards ("OK" first, "Cancel" second) when using an LTR language. The actual order in which the buttons will be placed depends on the current language and platform.

getLeadingAlignment

public static HasHorizontalAlignment.HorizontalAlignmentConstant getLeadingAlignment()

Returns the alignment constant corresponding to the beginning of the line in reading order.

getTrailingAlignment

public static HasHorizontalAlignment.HorizontalAlignmentConstant getTrailingAlignment()

Returns the alignment constant corresponding to the end of the line in reading order.

setTextDirection

public static void setTextDirection(Widget widget)

Sets the direction of the specified widget to the direction of the application's language.

setDataDirection

public static void setDataDirection(Widget widget)

Sets the direction of the specified widget to LTR.

setVisualWidth

public static void setVisualWidth(Widget widget,
                                  Object elementType,
                                  int width)

Sets the width of the specified widget so that its visual width is as specified. elementType if one of the UI element constants in GWTUiDefaults.

setVisualWidth

public static void setVisualWidth(Widget widget,
                                  int width)

Sets the width of the specified widget so that its visual width is as specified. This is different from setVisualWidth(Widget, Object, int) in that it guesses the element type of the widget itself, but only works for standard GWT widgets.

getHorizontalStrut

public static Widget getHorizontalStrut(int width)

Creates a horizontal spacer of the specified width.

getVerticalStrut

public static Widget getVerticalStrut(int height)

Creates a vertical spacer of the specified height.

getRigidArea

public static Widget getRigidArea(int width,
                                  int height)

Creates a spacer of the specified dimensions.

getRelatedHorizontalStrut

public static Widget getRelatedHorizontalStrut()

Returns a horizontal spacer of with the size of the preferred distance between related elements.

getUnrelatedHorizontalStrut

public static Widget getUnrelatedHorizontalStrut()

Returns a horizontal spacer of with the size of the preferred distance between unrelated elements.

getRelatedVerticalStrut

public static Widget getRelatedVerticalStrut()

Returns a vertical spacer of with the size of the preferred distance between related elements.

getUnrelatedVerticalStrut

public static Widget getUnrelatedVerticalStrut()

Returns a vertical spacer of with the size of the preferred distance between unrelated elements.

setAbsoluteFullSize

public static void setAbsoluteFullSize(Widget widget)

Sets the specified widget's position attribute to "absolute", its top and left attributes to "0px" and its width and height attributes to "100%".

setFullSize

public static void setFullSize(Widget widget)

Sets the specified widget's top and left attributes to "0px" and its width and height attributes to "100%".

addFullSize

public static void addFullSize(Panel panel,
                               Widget widget)

Adds the specified widget to the specified absolute panel and makes it occupy the panel fully.

setAbsoluteBounds

public static void setAbsoluteBounds(Widget widget,
                                     int left,
                                     int top,
                                     int width,
                                     int height)

Sets the bounds of the specified widget and its "position" style attribute to "absolute".

setBounds

public static void setBounds(Widget widget,
                             int left,
                             int top,
                             int width,
                             int height)

Sets the "left", "top", "width" and "height" attributes of the widget to the specified values, in pixels.

setContainingSize

public static void setContainingSize(AbsolutePanel panel)

Sets the bounds of the specified panel so that all of its widgets are within them (obviously, except those placed at negative coordinates).

addInCorner

public static void addInCorner(Panel panel,
                               Widget widget,
                               Alignment corner,
                               SizeView offset)

Adds the specified widget to the specified corner of the specified panel with the specified offset from the borders.

Parameters:

panel - The panel to add to.

widget - The widget to place in a corner.

corner - The corner to place the widget in. This must be one of the alignment constants which define a corner (not anything in the middle).

offset - The offset, in pixels, from the borders.

getTopLeft

public static Point getTopLeft(Widget widget)

Returns the top-left location of an absolutely positioned widget from its "top" and "left" style attributes. Note that this only works for absolutely positioned widgets.

setTopLeft

public static void setTopLeft(Widget widget,
                              PointView point)

Sets the widget's position via the "top" and "left" style attributes.

setTopLeft

public static void setTopLeft(Widget widget,
                              int x,
                              int y)

Sets the widget's position via the "top" and "left" style attributes.

disableContextMenu

public static void disableContextMenu(Element element)

Disables the browser context menu for the specified element (and enables right-click detection). Note that this is not reliable across browsers (Opera, for example, doesn't care and still displays the context menu).

setElementId

public static void setElementId(Widget widget,
                                String id)

Sets the id attribute of the specified widget's DOM element to the specified value.

getTagName

public static String getTagName(Element element)

Returns the tag name of the specified element.

findElementsByTagName

public static void findElementsByTagName(Element parent,
                                         String tagName,
                                         List list)

Finds the children of the specified element whose tag name is the specified one, and adds them to the specified list. Tag name comparison is done in a case-insensitive manner.

getPrimaryStyleName

public static String getPrimaryStyleName(String fullStyleName)

Returns the "primary" style name based on the specified full style name.

getPrimaryStyleName

public static String getPrimaryStyleName(Widget widget)

Returns the "primary" style name of the specified widget.

addDependentStyleName

public static void addDependentStyleName(Widget widget,
                                         String styleSuffix)

Adds a dependent style name to the specified widget. See UIObject.addStyleName(String) for a description of dependent styles.

Parameters:

styleSuffix - The suffix of the dependent style (not including the '-' separator).

setVisible

public static void setVisible(Widget widget,
                              boolean isVisible)

Sets the visibility of the specified widget. This is different from UIObject.setVisible(boolean) in that it uses the "visibility" CSS property, and not "display".

setZOrder

public static void setZOrder(Widget[] widgets)

Sets the z-indices of the specified widgets to their indices in the specified array, making widgets with greater indices appear on top of widgets with smaller indices.

setOpacity

public static void setOpacity(Widget widget,
                              double opacity)

Sets the opacity of the specified widget to the specified value, where 0 stands for completely transparent and 1 for completely opaque.

setGrabCursorUrl

public static void setGrabCursorUrl(String url)

Sets the grab cursor to the specified URL. This will be used by setGrabCursor(Widget).

setGrabbingCursorUrl

public static void setGrabbingCursorUrl(String url)

Sets the grabbing cursor to the specified URL. This will be used by setGrabbingCursor(Widget).

setGrabCursor

public static void setGrabCursor(Widget widget)

Sets the "grab" cursor on the specified widget, if supported. You can set the cursor to be used via setGrabCursorUrl(String).

setGrabbingCursor

public static void setGrabbingCursor(Widget widget)

Sets the "grabbing" cursor on the specified widget, if supported. You can set the cursor to be used via setGrabbingCursorUrl(String).

extraImageCellHeightWorkaround

public static void extraImageCellHeightWorkaround(Element tdElement)

Fixes a strange problem with an image being placed in a table cell. The problem is that there are extra 4 pixels below the image. Known anomalies, if you want to try and fix it: - If a DIV is put instead of an image, it works fine. - It works fine in HTML Transitional, but not Strict. - The behaviour is not due to GWT or anything - a plain HTML table also behaves this way. Note that tdElement must be an actual TD element.

extraImageCellHeightWorkaround

public static void extraImageCellHeightWorkaround(Widget panel)

Fixes the problem described by extraImageCellHeightWorkaround(Element) for every TD element of the specified panel.

fillRow

public static void fillRow(HTMLTable table,
                           int row,
                           int height)

Fills the specified row of a table with vertical struts of the specified size. Note that the row must already exist.

prepareLayoutTable

public static HTMLTable prepareLayoutTable(HTMLTable table)

Prepares the specified table to be a layout table by clearing its cell padding, spacing and border.

trackResizes

public static Object trackResizes(Widget widget,
                                  ChangeListener listener)

Attempts to track changes in the size of the specified widget and notify the specified change listener. Note that there isn't much we can actually do to get notified when the size changes - what we do is listen to size changes of the containing window, and look if the size of the widget changed as well. It's not good, but it's better than nothing. Note that when you are done with the widget, you should invoke stopTrackingResizes(Object) with the object returned by this method, to clean-up and avoid memory leaks.

Returns:

an object you can pass to stopTrackingResizes(Object) to stop tracking resizes.

stopTrackingResizes

public static void stopTrackingResizes(Object resizeTracker)

Stops tracking size changes for some widget. The argument taken by this method is the object returned by trackResizes(Widget, ChangeListener). You should call this method when the widget of interest is no longer used, to avoid memory leaks.

cancelCurrentEvent

public static void cancelCurrentEvent()

Cancels processing of the current event by cancalling bubble and preventing the default action on event from occurring.

makeDraggable

public static Object makeDraggable(Widget widget,
                                   SourcesMouseEvents dragHandle,
                                   DragAction dragAction)

Makes the specified widget draggable via the specified drag handle. The dragging will also be reported to the specified DragAction, if not null, with all parameters passed being relative to the parent of the dragged widget. That is, the drag target widget will be the parent and the pressed point and offset will be relative to the parent. You may make the widget un-draggable again by passing the return value to disableDragging(Object).

disableDragging

public static void disableDragging(Object dragTracker)

Makes the specified widget un-draggable, after it was made draggable with makeDraggable(Widget, SourcesMouseEvents, DragAction).

Parameters:

dragTracker - The object returned by makeDraggable.

applyPngHack

public static void applyPngHack(Image image,
                                String url,
                                Size size)

Applies the IE PNG hack to the specified image. When using the PNG hack, never call Image.setUrl(String) directly; always use this method instead. Also, using Image.getUrl() on a PNG-hacked image will not return the expected URL. You don't have to, but are advised to specify the image's size - the PNG hack is only 100% reliable if you do.

Parameters:

image - The image to apply the PNG hack to.

url - The URL of the PNG image.

size - The size of the image; may be null.

getPngHackedImageHtml

public static String getPngHackedImageHtml(String url,
                                           Size size)

Returns the HTML for an image at the specified URL with the PNG hack applied to it. You don't have to, but are advised to specify the image's size - the PNG hack is only 100% reliable if you do.