Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Innoopract Informationssysteme GmbH - initial API and implementation * EclipseSource - ongoing development ******************************************************************************/ package org.eclipse.swt.widgets; import java.text.NumberFormat; import org.eclipse.rap.rwt.RWT; import org.eclipse.rap.rwt.internal.lifecycle.WidgetLCA; import org.eclipse.rap.rwt.internal.textsize.TextSizeUtil; import org.eclipse.rap.rwt.internal.theme.ThemeAdapter; import org.eclipse.rap.rwt.theme.BoxDimensions; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.events.ModifyListener; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.internal.widgets.spinnerkit.SpinnerLCA; import org.eclipse.swt.internal.widgets.spinnerkit.SpinnerThemeAdapter; /** * Instances of this class are selectable user interface * objects that allow the user to enter and modify numeric * values. * <p> * <dl> * <dt><b>Styles:</b></dt> * <dd>READ_ONLY, WRAP</dd> * <dt><b>Events:</b></dt> * <dd>Selection, Modify</dd> * </dl> * </p><p> * IMPORTANT: This class is <em>not</em> intended to be subclassed. * </p> * @since 1.0 */ public class Spinner extends Composite { /** * the <!-- operating system --> limit for the number of characters * that the text field in an instance of this class can hold * * @since 1.3 */ public static final int LIMIT = Integer.MAX_VALUE; private static final int UP_DOWN_MIN_HEIGHT = 18; private int minimum; private int maximum; private int digits; private int increment; private int pageIncrement; private int selection; private int textLimit; /** * Constructs a new instance of this class given its parent * and a style value describing its behavior and appearance. * <p> * The style value is either one of the style constants defined in * class <code>SWT</code> which is applicable to instances of this * class, or must be built by <em>bitwise OR</em>'ing together * (that is, using the <code>int</code> "|" operator) two or more * of those <code>SWT</code> style constants. The class description * lists the style constants that are applicable to the class. * Style bits are also inherited from superclasses. * </p> * * @param parent a composite control which will be the parent of the new instance (cannot be null) * @param style the style of control to construct * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> * <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li> * </ul> * * @see SWT#READ_ONLY * @see SWT#WRAP * @see Widget#checkSubclass * @see Widget#getStyle */ public Spinner(Composite parent, int style) { super(parent, checkStyle(style)); minimum = 0; maximum = 100; digits = 0; increment = 1; pageIncrement = 10; selection = 0; textLimit = LIMIT; } @Override void initState() { removeState( /* CANVAS | */ THEME_BACKGROUND); } /** * Returns the number of decimal places used by the receiver. * * @return the digits * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getDigits() { checkWidget(); return digits; } /** * Sets the number of decimal places used by the receiver. * <p> * The digit setting is used to allow for floating point values in the receiver. * For example, to set the selection to a floating point value of 1.37 call setDigits() with * a value of 2 and setSelection() with a value of 137. Similarly, if getDigits() has a value * of 2 and getSelection() returns 137 this should be interpreted as 1.37. This applies to all * numeric APIs. * </p> * * @param value the new digits (must be greater than or equal to zero) * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the value is less than zero</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @since 1.3 */ public void setDigits(int value) { checkWidget(); if (value < 0) { error(SWT.ERROR_INVALID_ARGUMENT); } digits = value; } ///////////////////////////////////////// // Methods to control range and increment /** * Returns the amount that the receiver's value will be * modified by when the up/down arrows are pressed. * * @return the increment * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getIncrement() { checkWidget(); return increment; } /** * Sets the amount that the receiver's value will be * modified by when the up/down arrows are pressed to * the argument, which must be at least one. * * @param value the new increment (must be greater than zero) * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public void setIncrement(int value) { checkWidget(); if (value >= 1) { increment = value; } } /** * Returns the minimum value which the receiver will allow. * * @return the minimum * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getMinimum() { checkWidget(); return minimum; } /** * Sets the minimum value that the receiver will allow. This new * value will be ignored if it is greater than the receiver's * current maximum value. If the new minimum is applied then the receiver's * selection value will be adjusted if necessary to fall within its new range. * * @param value the new minimum, which must be less than or equals to the current maximum * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public void setMinimum(int value) { checkWidget(); if (value <= maximum) { minimum = value; if (selection < minimum) { selection = minimum; } } } /** * Returns the maximum value which the receiver will allow. * * @return the maximum * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getMaximum() { checkWidget(); return maximum; } /** * Sets the maximum value that the receiver will allow. This new * value will be ignored if it is less than the receiver's current * minimum value. If the new maximum is applied then the receiver's * selection value will be adjusted if necessary to fall within its new range. * * @param value the new maximum, which must be greater than or equal to the current minimum * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public void setMaximum(int value) { checkWidget(); if (value >= minimum) { maximum = value; if (selection > maximum) { selection = maximum; } } } /** * Returns the amount that the receiver's position will be * modified by when the page up/down keys are pressed. * * @return the page increment * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getPageIncrement() { checkWidget(); return pageIncrement; } /** * Sets the amount that the receiver's position will be * modified by when the page up/down keys are pressed * to the argument, which must be at least one. * * @param value the page increment (must be greater than zero) * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public void setPageIncrement(int value) { checkWidget(); if (value >= 1) { pageIncrement = value; } } /** * Returns the <em>selection</em>, which is the receiver's position. * * @return the selection * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getSelection() { checkWidget(); return selection; } /** * Sets the <em>selection</em>, which is the receiver's * position, to the argument. If the argument is not within * the range specified by minimum and maximum, it will be * adjusted to fall within this range. * * @param value the new selection (must be zero or greater) * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public void setSelection(int value) { checkWidget(); selection = Math.min(Math.max(minimum, value), maximum); notifyListeners(SWT.Modify, new Event()); } /** * Sets the receiver's selection, minimum value, maximum * value, digits, increment and page increment all at once. * <p> * Note: This is similar to setting the values individually * using the appropriate methods, but may be implemented in a * more efficient fashion on some platforms. * </p> * * @param selection the new selection value * @param minimum the new minimum value * @param maximum the new maximum value * @param digits the new digits value * @param increment the new increment value * @param pageIncrement the new pageIncrement value * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public void setValues(int selection, int minimum, int maximum, int digits, int increment, int pageIncrement) { checkWidget(); if (maximum >= minimum && digits >= 0 && increment >= 1 && pageIncrement >= 1) { this.minimum = minimum; this.maximum = maximum; this.digits = digits; this.increment = increment; this.pageIncrement = pageIncrement; setSelection(selection); } } /** * Returns a string containing a copy of the contents of the * receiver's text field, or an empty string if there are no * contents. * * @return the receiver's text * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @since 1.3 */ public String getText() { checkWidget(); String result = String.valueOf(selection); if (digits > 0) { NumberFormat nf = NumberFormat.getInstance(RWT.getLocale()); nf.setMinimumFractionDigits(digits); nf.setMaximumFractionDigits(digits); result = nf.format(selection / Math.pow(10, digits)); } return result; } /** * Sets the maximum number of characters that the receiver * is capable of holding to be the argument. * <p> * Instead of trying to set the text limit to zero, consider * creating a read-only text widget. * </p><p> * To reset this value to the default, use <code>setTextLimit(Text.LIMIT)</code>. * Specifying a limit value larger than <code>Text.LIMIT</code> sets the * receiver's limit to <code>Text.LIMIT</code>. * </p> * * @param textLimit new text limit * * @exception IllegalArgumentException <ul> * <li>ERROR_CANNOT_BE_ZERO - if the limit is zero</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see #LIMIT * @since 1.3 */ public void setTextLimit(int textLimit) { checkWidget(); if (textLimit == 0) { error(SWT.ERROR_CANNOT_BE_ZERO); } // Note that we mimic here the behavior of SWT Text with style MULTI on // Windows. In SWT, other operating systems and/or style flags behave // different. this.textLimit = textLimit; } /** * Returns the maximum number of characters that the receiver is capable of holding. * <p> * If this has not been changed by <code>setTextLimit()</code>, * it will be the constant <code>Text.LIMIT</code>. * </p> * * @return the text limit * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see #LIMIT * @since 1.3 */ public int getTextLimit() { checkWidget(); return textLimit; } /////////////////// // Size calculation @Override public Point computeSize(int wHint, int hHint, boolean changed) { checkWidget(); int width = 0; int height = 0; if (wHint == SWT.DEFAULT || hHint == SWT.DEFAULT) { int maxValue = Math.max(Math.abs(maximum), Math.abs(minimum)); String string = String.valueOf(maxValue); if (digits > 0) { StringBuilder buffer = new StringBuilder(); buffer.append(string); buffer.append(","); int count = digits - string.length(); while (count >= 0) { buffer.append("0"); count--; } string = buffer.toString(); } if (minimum < 0 || maximum < 0) { string += "-"; } Point textSize = TextSizeUtil.stringExtent(getFont(), string); BoxDimensions padding = getFieldPadding(); int buttonWidth = getButtonWidth(); width = textSize.x + buttonWidth + padding.left + padding.right; height = textSize.y + padding.top + padding.bottom; } if (width == 0) { width = DEFAULT_WIDTH; } if (height == 0) { height = DEFAULT_HEIGHT; } if (wHint != SWT.DEFAULT) { width = wHint; } if (hHint != SWT.DEFAULT) { height = hHint; } Rectangle trim = computeTrim(0, 0, width, height); if (hHint == SWT.DEFAULT) { BoxDimensions border = getBorder(); int upDownHeight = UP_DOWN_MIN_HEIGHT + border.top + border.bottom; trim.height = Math.max(trim.height, upDownHeight); } return new Point(trim.width, trim.height); } @Override public Rectangle computeTrim(int x, int y, int width, int height) { checkWidget(); Rectangle result = new Rectangle(x, y, width, height); if ((style & SWT.BORDER) != 0) { BoxDimensions border = getBorder(); result.x -= border.left; result.y -= border.top; result.width += border.left + border.right; result.height += border.top + border.bottom; } int buttonWidth = getButtonWidth(); result.width += buttonWidth; return result; } ///////////////////////////////////////////// // Event listener registration/deregistration /** * Adds the listener to the collection of listeners who will * be notified when the receiver's text is modified, by sending * it one of the messages defined in the <code>ModifyListener</code> * interface. * * @param listener the listener which should be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see ModifyListener * @see #removeModifyListener */ public void addModifyListener(ModifyListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } TypedListener typedListener = new TypedListener(listener); addListener(SWT.Modify, typedListener); } /** * Removes the listener from the collection of listeners who will * be notified when the receiver's text is modified. * * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see ModifyListener * @see #addModifyListener */ public void removeModifyListener(ModifyListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } removeListener(SWT.Modify, listener); } /** * Adds the listener to the collection of listeners who will * be notified when the control is selected by the user, by sending * it one of the messages defined in the <code>SelectionListener</code> * interface. * <p> * <code>widgetSelected</code> is not called for texts. * <code>widgetDefaultSelected</code> is typically called when ENTER is pressed in a single-line text. * </p> * * @param listener the listener which should be notified when the control is selected by the user * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see SelectionListener * @see #removeSelectionListener * @see SelectionEvent * * @since 1.2 */ public void addSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } TypedListener typedListener = new TypedListener(listener); addListener(SWT.Selection, typedListener); addListener(SWT.DefaultSelection, typedListener); } /** * Removes the listener from the collection of listeners who will * be notified when the control is selected by the user. * * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see SelectionListener * @see #addSelectionListener * * @since 1.2 */ public void removeSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } removeListener(SWT.Selection, listener); removeListener(SWT.DefaultSelection, listener); } @Override @SuppressWarnings("unchecked") public <T> T getAdapter(Class<T> adapter) { if (adapter == WidgetLCA.class) { return (T) SpinnerLCA.INSTANCE; } return super.getAdapter(adapter); } ////////////////// // Helping methods private BoxDimensions getFieldPadding() { return getThemeAdapter().getFieldPadding(this); } private int getButtonWidth() { return getThemeAdapter().getButtonWidth(this); } private SpinnerThemeAdapter getThemeAdapter() { return (SpinnerThemeAdapter) getAdapter(ThemeAdapter.class); } private static int checkStyle(int style) { /* * Even though it is legal to create this widget * with scroll bars, they serve no useful purpose * because they do not automatically scroll the * widget's client area. The fix is to clear * the SWT style. */ return style & ~(SWT.H_SCROLL | SWT.V_SCROLL); } }