/**
* Copyright (c) 2013 Nokia Corporation. All rights reserved. Nokia and Nokia
* Connecting People are registered trademarks of Nokia Corporation. Oracle and
* Java are trademarks or registered trademarks of Oracle and/or its affiliates.
* Other product and company names mentioned herein may be trademarks or trade
* names of their respective owners. See LICENSE.TXT for license information.
*/
package com.nokia.example.musicexplorer.ui;
import java.util.Enumeration;
import java.util.Vector;
import javax.microedition.lcdui.CustomItem;
import javax.microedition.lcdui.Graphics;
import com.nokia.example.musicexplorer.data.model.GenericProductModel;
import com.nokia.example.musicexplorer.data.model.AlbumModel;
/**
* GridLayout is a CustomItem component for displaying a grid of GridItems in a
* Form.
*/
public class GridLayout extends CustomItem {
public static final int CUSTOM_ITEM_MARGIN_SIZE = 5;
public static final int DEFAULT_COLUMN_COUNT = 3;
public static final int JITTER_THRESHOLD = 10;
protected Vector gridItems;
protected GridItem selectedItem;
protected int width = 0;
protected int columnCount = DEFAULT_COLUMN_COUNT;
protected int columnWidth = 0;
protected int rowHeight = 0;
protected int lastX = 0;
protected int lastY = 0;
protected int verticalScrollPosition = 0;
protected ViewManager viewManager;
protected boolean showMoreByArtistButton = true;
/**
* Constructor.
* @param width
* @param viewManager
*/
public GridLayout(final int width, ViewManager viewManager) {
super(null);
this.viewManager = viewManager;
this.gridItems = new Vector();
setWidth(width);
}
/**
* Adds an item to the grid.
*
* @param productModel
*/
public void addItem(GenericProductModel productModel) {
GridItem gridItem = new GridItem(viewManager, productModel, this);
gridItem.setSize(columnWidth, columnWidth);
gridItems.addElement(gridItem);
int amountOfRows = (int) Math.ceil(
(double) gridItems.size() / this.columnCount);
int newHeight =
amountOfRows * this.rowHeight + CUSTOM_ITEM_MARGIN_SIZE * 2;
this.setPreferredSize(this.width, newHeight);
repaint();
}
/**
* Adds a vector of ProductModels to the grid at once.
* @param productModels
*/
public void addItems(Vector productModels) {
int loopMax = productModels.size();
for (int i = 0; i < loopMax; i++) {
addItem((GenericProductModel) productModels.elementAt(i));
}
}
/**
* For convenience. Calculates the size and repaints the layout only once.
*
* @param columnCount The new column count.
* @param width The new width for the layout.
*/
public void setColumnCountAndWidth(final int columnCount, final int width) {
if ((this.width != width && columnCount > 0)
|| (columnCount > 0 && this.columnCount != columnCount)) {
this.columnCount = columnCount;
this.width = width;
onWidthOrColumnCountChanged();
}
}
/**
* @param width The new width for the layout.
*/
public void setWidth(final int width) {
if (this.width != width) {
this.width = width;
onWidthOrColumnCountChanged();
}
}
/**
* Sets the number of columns to be displayed in the grid.
*
* @param columnCount The number of columns.
*/
public void setColumnCount(final int columnCount) {
if (columnCount > 0 && this.columnCount != columnCount) {
this.columnCount = columnCount;
onWidthOrColumnCountChanged();
}
}
/**
* Get the grid item under the pointer and set it as {@link #selectedItem}.
*
* @see javax.microedition.lcdui.CustomItem#pointerPressed()
*/
public void pointerPressed(int x, int y) {
selectedItem = getItemAt(x, y);
if (selectedItem != null) {
// Save the coordinates to be used in pointerReleased().
lastX = x;
lastY = y;
selectedItem.setHighlight(true);
}
}
/**
* Checks if the pointer is still inside the same item where the tap began
* on.
*
* @see javax.microedition.lcdui.CustomItem#pointerReleased()
*/
public void pointerReleased(int x, int y) {
if (selectedItem != null && selectedItem == getItemAt(x, y)
&& Math.abs(x - lastX) < JITTER_THRESHOLD
&& Math.abs(y - lastY) < JITTER_THRESHOLD) {
selectedItem.setHighlight(false);
viewManager.showView(
new AlbumView(
viewManager,
(AlbumModel) selectedItem.model,
showMoreByArtistButton));
}
}
/**
* Clears the {@link #selectedItem} when pointer is dragged outside the grid
* item.
*
* @see javax.microedition.lcdui.CustomItem#pointerDragged()
*/
public void pointerDragged(int x, int y) {
if (selectedItem != null
&& (Math.abs(x - lastX) > JITTER_THRESHOLD
|| Math.abs(y - lastY) > JITTER_THRESHOLD)) {
// Too much jitter. Loose the selected item.
selectedItem.setHighlight(false);
selectedItem = null;
repaint(); // Must be repainted to hide highlight on item.
}
}
public void disableShowMoreByArtistButtonInAlbumViews() {
this.showMoreByArtistButton = false;
}
/**
* @see javax.microedition.lcdui.CustomItem#getMinContentHeight()
*/
protected int getMinContentHeight() {
return 0;
}
/**
* @see javax.microedition.lcdui.CustomItem#getMinContentWidth()
*/
protected int getMinContentWidth() {
return 0;
}
/**
* @see javax.microedition.lcdui.CustomItem#getPrefContentHeight(int)
*/
protected int getPrefContentHeight(int h) {
return getPreferredHeight();
}
/**
* @see javax.microedition.lcdui.CustomItem#getPrefContentWidth(int)
*/
protected int getPrefContentWidth(int w) {
return getPreferredWidth();
}
/**
* @see javax.microedition.lcdui.CustomItem#paint(Graphics, int, int)
*/
protected void paint(Graphics graphics, int width, int height) {
Enumeration e = gridItems.elements();
int row = 0;
int col = 0;
// Loop the grid items
while (e.hasMoreElements()) {
GridItem item = (GridItem) e.nextElement();
// Paint the current item
item.paintXY(graphics, col * columnWidth, row * rowHeight);
col++;
// Advance to the next row if all columns have been painted
if (col == columnCount) {
row++;
col = 0;
}
}
}
/**
* Resolves an item at the given position.
*
* @param x The X coordinate of the item.
* @param y The Y coordinate of the item.
* @return The item instance in the given position or null if not found.
*/
protected GridItem getItemAt(int x, int y) {
// Calculate item index based on coordinates.
final int col = x / columnWidth;
final int row = y / rowHeight;
final int index = (columnCount * row) + col;
GridItem item = null;
int size = gridItems.size();
// Check if index is in range.
if (index < size) {
item = (GridItem) gridItems.elementAt(index);
}
return item;
}
/**
* (Re)calculates the column width and the preferred size for the layout and
* repaints the whole thing.
*/
protected void onWidthOrColumnCountChanged() {
columnWidth = (width - CUSTOM_ITEM_MARGIN_SIZE * 2) / columnCount;
rowHeight = columnWidth; // Only square items
Enumeration e = gridItems.elements();
while (e.hasMoreElements()) {
((GridItem) e.nextElement()).setSize(columnWidth, rowHeight);
}
final int rowCount = (int) Math.ceil((double) gridItems.size() / columnCount);
setPreferredSize(width, rowCount * rowHeight + CUSTOM_ITEM_MARGIN_SIZE * 2);
repaint();
}
/**
* For toggling grid repaint.
*/
public void gridItemStateChanged() {
repaint();
}
}