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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Eclipse Public License, Version 1.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.eclipse.org/org/documents/epl-v10.php
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.ide.eclipse.adt.internal.editors.uimodel;
     18 
     19 import com.android.ide.eclipse.adt.internal.editors.descriptors.AttributeDescriptor;
     20 
     21 import org.w3c.dom.Node;
     22 
     23 /**
     24  * Represents an XML attribute in that can be modified using a simple text field
     25  * in the XML editor's user interface.
     26  * <p/>
     27  * The XML attribute has no default value. When unset, the text field is blank.
     28  * When updating the XML, if the field is empty, the attribute will be removed
     29  * from the XML element.
     30  * <p/>
     31  * See {@link UiAttributeNode} for more information.
     32  */
     33 public abstract class UiAbstractTextAttributeNode extends UiAttributeNode
     34     implements IUiSettableAttributeNode {
     35 
     36     protected static final String DEFAULT_VALUE = "";  //$NON-NLS-1$
     37 
     38     /** Prevent internal listener from firing when internally modifying the text */
     39     private boolean mInternalTextModification;
     40     /** Last value read from the XML model. Cannot be null. */
     41     private String mCurrentValue = DEFAULT_VALUE;
     42 
     43     public UiAbstractTextAttributeNode(AttributeDescriptor attributeDescriptor,
     44             UiElementNode uiParent) {
     45         super(attributeDescriptor, uiParent);
     46     }
     47 
     48     /** Returns the current value of the node. */
     49     @Override
     50     public final String getCurrentValue() {
     51         return mCurrentValue;
     52     }
     53 
     54     /** Sets the current value of the node. Cannot be null (use an empty string). */
     55     @Override
     56     public final void setCurrentValue(String value) {
     57         mCurrentValue = value;
     58     }
     59 
     60     /** Returns if the attribute node is valid, and its UI has been created. */
     61     public abstract boolean isValid();
     62 
     63     /** Returns the text value present in the UI. */
     64     public abstract String getTextWidgetValue();
     65 
     66     /** Sets the text value to be displayed in the UI. */
     67     public abstract void setTextWidgetValue(String value);
     68 
     69 
     70     /**
     71      * Updates the current text field's value when the XML has changed.
     72      * <p/>
     73      * The caller doesn't really know if attributes have changed,
     74      * so it will call this to refresh the attribute anyway. The value
     75      * is only set if it has changed.
     76      * <p/>
     77      * This also resets the "dirty" flag.
     78     */
     79     @Override
     80     public void updateValue(Node xml_attribute_node) {
     81         mCurrentValue = DEFAULT_VALUE;
     82         if (xml_attribute_node != null) {
     83             mCurrentValue = xml_attribute_node.getNodeValue();
     84         }
     85 
     86         if (isValid() && !getTextWidgetValue().equals(mCurrentValue)) {
     87             try {
     88                 mInternalTextModification = true;
     89                 setTextWidgetValue(mCurrentValue);
     90                 setDirty(false);
     91             } finally {
     92                 mInternalTextModification = false;
     93             }
     94         }
     95     }
     96 
     97     /* (non-java doc)
     98      * Called by the user interface when the editor is saved or its state changed
     99      * and the modified attributes must be committed (i.e. written) to the XML model.
    100      */
    101     @Override
    102     public void commit() {
    103         UiElementNode parent = getUiParent();
    104         if (parent != null && isValid() && isDirty()) {
    105             String value = getTextWidgetValue();
    106             if (parent.commitAttributeToXml(this, value)) {
    107                 mCurrentValue = value;
    108                 setDirty(false);
    109             }
    110         }
    111     }
    112 
    113     protected final boolean isInInternalTextModification() {
    114         return mInternalTextModification;
    115     }
    116 
    117     protected final void setInInternalTextModification(boolean internalTextModification) {
    118         mInternalTextModification = internalTextModification;
    119     }
    120 }
    121