ListPicker.java

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// -*- mode: java; c-basic-offset: 2; -*-
// Copyright 2009-2011 Google, All Rights reserved
// Copyright 2011-2012 MIT, All rights reserved
// Released under the Apache License, Version 2.0
// http://www.apache.org/licenses/LICENSE-2.0
 
package com.google.appinventor.components.runtime;
 
import com.google.appinventor.components.annotations.DesignerComponent;
import com.google.appinventor.components.annotations.DesignerProperty;
import com.google.appinventor.components.annotations.IsColor;
import com.google.appinventor.components.annotations.PropertyCategory;
import com.google.appinventor.components.annotations.SimpleObject;
import com.google.appinventor.components.annotations.SimpleProperty;
import com.google.appinventor.components.annotations.UsesActivities;
import com.google.appinventor.components.annotations.androidmanifest.ActivityElement;
import com.google.appinventor.components.common.ComponentCategory;
import com.google.appinventor.components.common.PropertyTypeConstants;
import com.google.appinventor.components.common.YaVersion;
import com.google.appinventor.components.runtime.util.ElementsUtil;
import com.google.appinventor.components.runtime.util.YailList;
 
import android.app.Activity;
import android.content.Intent;
import android.view.WindowManager;
 
@DesignerComponent(version = YaVersion.LISTPICKER_COMPONENT_VERSION,
    category = ComponentCategory.USERINTERFACE,
    description = "<p>A button that, when clicked on, displays a list of " +
    "texts for the user to choose among. The texts can be specified through " +
    "the Designer or Blocks Editor by setting the " +
    "<code>ElementsFromString</code> property to their string-separated " +
    "concatenation (for example, <em>choice 1, choice 2, choice 3</em>) or " +
    "by setting the <code>Elements</code> property to a List in the Blocks " +
    "editor.</p>" +
    "<p>Setting property ShowFilterBar to true, will make the list searchable.  " +
    "Other properties affect the appearance of the button " +
    "(<code>TextAlignment</code>, <code>BackgroundColor</code>, etc.) and " +
    "whether it can be clicked on (<code>Enabled</code>).</p>")
@SimpleObject
@UsesActivities(activities = {
    @ActivityElement(name = "com.google.appinventor.components.runtime.ListPickerActivity",
                     configChanges = "orientation|keyboardHidden",
                     screenOrientation = "behind")
})
public class ListPicker extends Picker implements ActivityResultListener, Deleteable, OnResumeListener {
 
  private static final String LIST_ACTIVITY_CLASS = ListPickerActivity.class.getName();
  static final String LIST_ACTIVITY_ARG_NAME = LIST_ACTIVITY_CLASS + ".list";
  static final String LIST_ACTIVITY_RESULT_NAME = LIST_ACTIVITY_CLASS + ".selection";
  static final String LIST_ACTIVITY_RESULT_INDEX = LIST_ACTIVITY_CLASS + ".index";
  static final String LIST_ACTIVITY_ANIM_TYPE = LIST_ACTIVITY_CLASS + ".anim";
  static final String LIST_ACTIVITY_SHOW_SEARCH_BAR = LIST_ACTIVITY_CLASS + ".search";
  static final String LIST_ACTIVITY_TITLE = LIST_ACTIVITY_CLASS + ".title";
  static final String LIST_ACTIVITY_ORIENTATION_TYPE = LIST_ACTIVITY_CLASS + ".orientation";
  static final String LIST_ACTIVITY_ITEM_TEXT_COLOR = LIST_ACTIVITY_CLASS + ".itemtextcolor";
  static final String LIST_ACTIVITY_BACKGROUND_COLOR = LIST_ACTIVITY_CLASS + ".backgroundcolor";
 
  private YailList items;
  private String selection;
  private int selectionIndex;
  private boolean showFilter =false;
  private static final boolean DEFAULT_ENABLED = false;
  private String title = "";    // The Title to display the List Picker with
                                // if left blank, the App Name is used instead
  private boolean resumedFromListFlag  = false; //flag so onResume knows if the resume was triggered by closing the listpicker activity
 
  private int itemTextColor;
  private int itemBackgroundColor;
  public final static int DEFAULT_ITEM_TEXT_COLOR = Component.COLOR_WHITE;
  public final static int DEFAULT_ITEM_BACKGROUND_COLOR = Component.COLOR_BLACK;
 
  public ListPicker(ComponentContainer container) {
    super(container);
    items = new YailList();
    // initialize selectionIndex which also sets selection
    SelectionIndex(0);
    itemTextColor = DEFAULT_ITEM_TEXT_COLOR;
    itemBackgroundColor = DEFAULT_ITEM_BACKGROUND_COLOR;
 
    container.$form().registerForOnResume(this);
  }
 
  @Override
  public void onResume() {
    if (resumedFromListFlag) {
      container.$form().getWindow().setSoftInputMode(
              WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN
      );
      resumedFromListFlag = false;
    }
  }
 
  @SimpleProperty(
      description = "The selected item.  When directly changed by the " +
      "programmer, the SelectionIndex property is also changed to the first " +
      "item in the ListPicker with the given value.  If the value does not " +
      "appear, SelectionIndex will be set to 0.",
      category = PropertyCategory.BEHAVIOR)
  public String Selection() {
    return selection;
  }
 
  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_STRING,
      defaultValue = "")
  @SimpleProperty
  public void Selection(String value) {
    selection = value;
    // Now, we need to change SelectionIndex to correspond to Selection.
    selectionIndex = ElementsUtil.setSelectedIndexFromValue(value, items);
  }
 
  @DesignerProperty(
    editorType = PropertyTypeConstants.PROPERTY_TYPE_BOOLEAN,
    defaultValue = DEFAULT_ENABLED ? "True" : "False")
  @SimpleProperty
  public void ShowFilterBar(boolean showFilter) {
    this.showFilter = showFilter;
  }
 
  @SimpleProperty(category = PropertyCategory.BEHAVIOR,
      description = "Returns current state of ShowFilterBar indicating if " +
          "Search Filter Bar will be displayed on ListPicker or not")
  public boolean ShowFilterBar() {
    return showFilter;
  }
 
  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_COLOR,
      defaultValue = Component.DEFAULT_VALUE_COLOR_WHITE)
  @SimpleProperty
  public void ItemTextColor(int argb) {
    this.itemTextColor = argb;
  }
 
  @SimpleProperty(description = "The text color of the ListPicker items.",
      category = PropertyCategory.APPEARANCE)
  @IsColor
  public int ItemTextColor() {
    return this.itemTextColor;
  }
 
  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_COLOR,
      defaultValue = Component.DEFAULT_VALUE_COLOR_BLACK)
  @SimpleProperty
  public void ItemBackgroundColor(int argb) {
    this.itemBackgroundColor = argb;
  }
 
  @SimpleProperty(description = "The background color of the ListPicker items.",
      category = PropertyCategory.APPEARANCE)
  @IsColor
  public int ItemBackgroundColor() {
    return this.itemBackgroundColor;
  }
 
  @SimpleProperty(
      description = "The index of the currently selected item, starting at " +
      "1.  If no item is selected, the value will be 0.  If an attempt is " +
      "made to set this to a number less than 1 or greater than the number " +
      "of items in the ListPicker, SelectionIndex will be set to 0, and " +
      "Selection will be set to the empty text.",
      category = PropertyCategory.BEHAVIOR)
  public int SelectionIndex() {
    return selectionIndex;
  }
 
  // Not a designer property, since this could lead to unpredictable
  // results if Selection is set to an incompatible value.
  @SimpleProperty
  public void SelectionIndex(int index) {
    selectionIndex = ElementsUtil.selectionIndex(index, items);
    // Now, we need to change Selection to correspond to SelectionIndex.
    selection = ElementsUtil.setSelectionFromIndex(index, items);
  }
 
  @SimpleProperty(category = PropertyCategory.BEHAVIOR)
  public YailList Elements() {
    return items;
  }
 
  // TODO(user): we need a designer property for lists
  @SimpleProperty
  public void Elements(YailList itemList) {
    items = ElementsUtil.elements(itemList, "ListPicker");
  }
 
  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_TEXTAREA,
                    defaultValue = "")
  // TODO(sharon): it might be nice to have a list editorType where the developer
  // could directly enter a list of strings (e.g. one per row) and we could
  // avoid the comma-separated business.
  @SimpleProperty(category = PropertyCategory.BEHAVIOR)
  public void ElementsFromString(String itemstring) {
    items = ElementsUtil.elementsFromString(itemstring);
  }
 
    @SimpleProperty(category = PropertyCategory.APPEARANCE,
                    description = "Optional title displayed at the top of the list of choices.")
  public String Title() {
    return title;
  }
 
  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_STRING,
      defaultValue = "")
  @SimpleProperty
  public void Title(String title) {
    this.title = title;
  }
 
  @Override
  public Intent getIntent() {
    Intent intent = new Intent();
    intent.setClassName(container.$context(), LIST_ACTIVITY_CLASS);
    intent.putExtra(LIST_ACTIVITY_ARG_NAME, items.toStringArray());
    intent.putExtra(LIST_ACTIVITY_SHOW_SEARCH_BAR, String.valueOf(showFilter)); //convert to string
    if (!title.equals("")) {
      intent.putExtra(LIST_ACTIVITY_TITLE, title);
    }
    // Get the current Form's opening transition anim type,
    // and pass it to the list picker activity. For consistency,
    // the closing animation will be the same (but in reverse)
    String openAnim = container.$form().getOpenAnimType();
    intent.putExtra(LIST_ACTIVITY_ANIM_TYPE, openAnim);
    intent.putExtra(LIST_ACTIVITY_ORIENTATION_TYPE,container.$form().ScreenOrientation());
    intent.putExtra(LIST_ACTIVITY_ITEM_TEXT_COLOR, itemTextColor);
    intent.putExtra(LIST_ACTIVITY_BACKGROUND_COLOR, itemBackgroundColor);
 
    return intent;
  }
 
  // ActivityResultListener implementation
 
  @Override
  public void resultReturned(int requestCode, int resultCode, Intent data) {
    if (requestCode == this.requestCode && resultCode == Activity.RESULT_OK) {
      if (data.hasExtra(LIST_ACTIVITY_RESULT_NAME)) {
        selection = data.getStringExtra(LIST_ACTIVITY_RESULT_NAME);
      } else {
        selection = "";
      }
      selectionIndex = data.getIntExtra(LIST_ACTIVITY_RESULT_INDEX, 0);
      AfterPicking();
      // It is necessary for the code of onResume to run there instead of here
      // because the activity has not yet been initialized at this point. At this
      // point, calls to the keyboard fail.
      resumedFromListFlag = true;
    }
  }
 
  // Deleteable implementation
 
  @Override
  public void onDelete() {
    container.$form().unregisterForActivityResult(this);
  }
 
}