Java tutorial
package org.drools.brms.client.modeldriven.ui; /* * Copyright 2005 JBoss Inc * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.List; import org.drools.brms.client.common.DirtyableComposite; import org.drools.brms.client.common.FieldEditListener; import org.drools.brms.client.common.FormStylePopup; import org.drools.brms.client.common.InfoPopup; import org.drools.brms.client.common.Lbl; import org.drools.brms.client.modeldriven.SuggestionCompletionEngine; import org.drools.brms.client.modeldriven.brl.FactPattern; import org.drools.brms.client.modeldriven.brl.ISingleFieldConstraint; import org.drools.brms.client.modeldriven.brl.RuleModel; import org.drools.brms.client.modeldriven.brl.SingleFieldConstraint; import com.google.gwt.user.client.Command; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.ChangeListener; import com.google.gwt.user.client.ui.ClickListener; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.HorizontalPanel; import com.google.gwt.user.client.ui.Image; import com.google.gwt.user.client.ui.KeyboardListener; import com.google.gwt.user.client.ui.ListBox; import com.google.gwt.user.client.ui.Panel; import com.google.gwt.user.client.ui.SimplePanel; import com.google.gwt.user.client.ui.TextBox; import com.google.gwt.user.client.ui.Widget; /** * This is an editor for constraint values. * How this behaves depends on the constraint value type. * When the constraint value has no type, it will allow the user to choose the first time. * * @author Michael Neale * @author Fernando Meyer */ public class ConstraintValueEditor extends DirtyableComposite { private final ISingleFieldConstraint constraint; private final Panel panel; private final RuleModel model; private final boolean numericValue; private String[] enumeratedValues; /** * @param con The constraint being edited. */ public ConstraintValueEditor(FactPattern pattern, String fieldName, ISingleFieldConstraint con, RuleModeller modeller, String valueType /* eg is numeric */) { this.constraint = con; if (valueType.equals(SuggestionCompletionEngine.TYPE_NUMERIC)) { this.numericValue = true; } else { this.numericValue = false; } if (valueType.equals(SuggestionCompletionEngine.TYPE_BOOLEAN)) { this.enumeratedValues = new String[] { "true", "false" }; } this.model = modeller.getModel(); SuggestionCompletionEngine sce = modeller.getSuggestionCompletions(); this.enumeratedValues = sce.getEnums(pattern, fieldName); panel = new SimplePanel(); refreshEditor(); initWidget(panel); } private void refreshEditor() { panel.clear(); if (constraint.constraintValueType == SingleFieldConstraint.TYPE_UNDEFINED) { Image clickme = new Image("images/edit.gif"); clickme.addClickListener(new ClickListener() { public void onClick(Widget w) { showTypeChoice(w, constraint); } }); panel.add(clickme); } else { switch (constraint.constraintValueType) { case SingleFieldConstraint.TYPE_LITERAL: panel.add(literalEditor()); break; case SingleFieldConstraint.TYPE_RET_VALUE: panel.add(returnValueEditor()); break; case SingleFieldConstraint.TYPE_VARIABLE: panel.add(variableEditor()); break; default: break; } } } private Widget variableEditor() { List vars = this.model.getBoundVariablesInScope(this.constraint); final ListBox box = new ListBox(); if (this.constraint.value == null) { box.addItem("Choose ..."); } for (int i = 0; i < vars.size(); i++) { String var = (String) vars.get(i); box.addItem(var); if (this.constraint.value != null && this.constraint.value.equals(var)) { box.setSelectedIndex(i); } } box.addChangeListener(new ChangeListener() { public void onChange(Widget w) { constraint.value = box.getItemText(box.getSelectedIndex()); } }); return box; } /** * An editor for the retval "formula" (expression). */ private Widget returnValueEditor() { TextBox box = boundTextBox(constraint); String msg = "This is a formula expression which will evaluate to a value."; Image img = new Image("images/function_assets.gif"); img.setTitle(msg); box.setTitle(msg); Widget ed = widgets(img, box); return ed; } /** * An editor for literal values. */ private Widget literalEditor() { //use a drop down if we have a fixed list if (this.enumeratedValues != null) { return enumDropDown(constraint.value, new ValueChanged() { public void valueChanged(String newValue) { constraint.value = newValue; } }, this.enumeratedValues); } else { final TextBox box = boundTextBox(constraint); if (this.numericValue) { box.addKeyboardListener(new KeyboardListener() { public void onKeyDown(Widget arg0, char arg1, int arg2) { } public void onKeyPress(Widget w, char c, int i) { if (Character.isLetter(c)) { ((TextBox) w).cancelKey(); } } public void onKeyUp(Widget arg0, char arg1, int arg2) { } }); } box.setTitle("This is a literal value. What is shown is what the field is checked against."); return box; } } /** * This will do a drop down for enumerated values.. */ public static Widget enumDropDown(//final ISingleFieldConstraint constraint, final String currentValue, final ValueChanged valueChanged, final String[] enumeratedValues) { final ListBox box = new ListBox(); if (currentValue == null || "".equals(currentValue)) { box.addItem("Choose ..."); } boolean selected = false; for (int i = 0; i < enumeratedValues.length; i++) { String v = enumeratedValues[i]; String val; if (v.indexOf('=') > 0) { //using a mapping String[] splut = splitValue(v); String realValue = splut[0]; String display = splut[1]; val = realValue; box.addItem(display, realValue); } else { box.addItem(v, v); val = v; } if (currentValue != null && currentValue.equals(val)) { box.setSelectedIndex(i); selected = true; } } if (currentValue != null && !selected) { //need to add this value box.addItem(currentValue, currentValue); box.setSelectedIndex(enumeratedValues.length); } box.addChangeListener(new ChangeListener() { public void onChange(Widget w) { valueChanged.valueChanged(box.getValue(box.getSelectedIndex())); //constraint.value = box.getValue( box.getSelectedIndex() ); } }); return box; } /** * 'Person.age' : ['M=Male', 'F=Female'] * * This will split the drop down item into a value and a key. * eg key=value * */ public static String[] splitValue(String v) { String[] s = new String[2]; int pos = v.indexOf('='); s[0] = v.substring(0, pos); s[1] = v.substring(pos + 1, v.length()); return s; } private TextBox boundTextBox(final ISingleFieldConstraint c) { final TextBox box = new TextBox(); box.setStyleName("constraint-value-Editor"); if (c.value == null) { box.setText(""); } else { box.setText(c.value); } if (c.value == null || c.value.length() < 5) { box.setVisibleLength(3); } else { box.setVisibleLength(c.value.length() - 1); } box.addChangeListener(new ChangeListener() { public void onChange(Widget w) { c.value = box.getText(); makeDirty(); } }); box.addKeyboardListener(new FieldEditListener(new Command() { public void execute() { box.setVisibleLength(box.getText().length()); } })); return box; } /** * Show a list of possibilities for the value type. */ private void showTypeChoice(Widget w, final ISingleFieldConstraint con) { final FormStylePopup form = new FormStylePopup("images/newex_wiz.gif", "Field value"); Button lit = new Button("Literal value"); lit.addClickListener(new ClickListener() { public void onClick(Widget w) { con.constraintValueType = SingleFieldConstraint.TYPE_LITERAL; doTypeChosen(form); } }); form.addAttribute("Literal value:", widgets(lit, new InfoPopup("Literal", "A literal value means the " + "constraint is directly against the value that you type (ie. what you see on screen)."))); form.addRow(new HTML("<hr/>")); form.addRow(new Lbl("Advanced options", "weak-Text")); //only want to show variables if we have some ! if (this.model.getBoundVariablesInScope(this.constraint).size() > 0) { Button variable = new Button("Bound variable"); variable.addClickListener(new ClickListener() { public void onClick(Widget w) { con.constraintValueType = SingleFieldConstraint.TYPE_VARIABLE; doTypeChosen(form); } }); form.addAttribute("A variable:", widgets(variable, new InfoPopup("A bound variable", "Will apply a constraint that compares a field to a bound variable."))); } Button formula = new Button("New formula"); formula.addClickListener(new ClickListener() { public void onClick(Widget w) { con.constraintValueType = SingleFieldConstraint.TYPE_RET_VALUE; doTypeChosen(form); } }); form.addAttribute("A formula:", widgets(formula, new InfoPopup("A formula", "A formula is an expression that calculates and returns a value " + ". That value is used to enforce the constraint."))); form.setPopupPosition(w.getAbsoluteLeft(), w.getAbsoluteTop()); form.show(); } private void doTypeChosen(final FormStylePopup form) { refreshEditor(); form.hide(); } private Panel widgets(Widget left, Widget right) { HorizontalPanel panel = new HorizontalPanel(); panel.add(left); panel.add(right); panel.setWidth("100%"); return panel; } public boolean isDirty() { return super.isDirty(); } static interface ValueChanged { public void valueChanged(String newValue); } }