ItemizedOverlayWithFocus.java

// Created by plusminus on 20:50:06 - 03.10.2008
package org.osmdroid.views.overlay;

import java.util.List;

import org.osmdroid.library.R;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.OverlayItem.HotspotPlace;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.TypedValue;

public class ItemizedOverlayWithFocus<Item extends OverlayItem> extends ItemizedIconOverlay<Item> {

	// ===========================================================
	// Constants
	// ===========================================================

	private final int DEFAULTMARKER_BACKGROUNDCOLOR = Color.rgb(101, 185, 74);


	// ===========================================================
	// Fields
	// ===========================================================

	private int DESCRIPTION_BOX_PADDING = 3;
	private int DESCRIPTION_BOX_CORNERWIDTH = 3;

	/** Additional to <code>DESCRIPTION_LINE_HEIGHT</code>. */
	private int DESCRIPTION_TITLE_EXTRA_LINE_HEIGHT = 2;

	private int FONT_SIZE_DP=14;
	private int DESCRIPTION_MAXWIDTH = 600;
	private int DESCRIPTION_LINE_HEIGHT = 30;

	protected int mMarkerFocusedBackgroundColor;
	protected Paint mMarkerBackgroundPaint, mDescriptionPaint, mTitlePaint;


	protected Drawable mMarkerFocusedBase;
	protected int mFocusedItemIndex;
	protected boolean mFocusItemsOnTap;
	private int fontSizePixels;
	private final Point mFocusedScreenCoords = new Point();

	private Context mContext;

	private String UNKNOWN;

	// ===========================================================
	// Constructors
	// ===========================================================

	public ItemizedOverlayWithFocus(final Context pContext, final List<Item> aList,
			final OnItemGestureListener<Item> aOnItemTapListener) {
		this(aList, aOnItemTapListener,pContext);
	}

	public ItemizedOverlayWithFocus(final List<Item> aList,
			final OnItemGestureListener<Item> aOnItemTapListener, Context pContext) {
		this(aList,
				pContext.getResources().getDrawable(R.drawable.marker_default)
				, null, NOT_SET,
				aOnItemTapListener, pContext);
	}

	public ItemizedOverlayWithFocus(final List<Item> aList, final Drawable pMarker,
			final Drawable pMarkerFocused, final int pFocusedBackgroundColor,
			final OnItemGestureListener<Item> aOnItemTapListener, Context pContext) {

		super(aList, pMarker, aOnItemTapListener, pContext);
		mContext = pContext;
		if (pMarkerFocused == null) {
			this.mMarkerFocusedBase = boundToHotspot(
					pContext.getResources().getDrawable(R.drawable.marker_default_focused_base)
					,
					HotspotPlace.BOTTOM_CENTER);
		} else
			this.mMarkerFocusedBase = pMarkerFocused;

		this.mMarkerFocusedBackgroundColor = (pFocusedBackgroundColor != NOT_SET) ? pFocusedBackgroundColor
				: DEFAULTMARKER_BACKGROUNDCOLOR;

		calculateDrawSettings();

		this.unSetFocusedItem();
	}

	private void calculateDrawSettings() {
		//calculate font size based on DP
		fontSizePixels= (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
				FONT_SIZE_DP, mContext.getResources().getDisplayMetrics());
		DESCRIPTION_LINE_HEIGHT=fontSizePixels+5;

		//calculate max width based on screen width.
		DESCRIPTION_MAXWIDTH=(int)(mContext.getResources().getDisplayMetrics().widthPixels*0.8);
		UNKNOWN = mContext.getResources().getString(R.string.unknown);

		this.mMarkerBackgroundPaint = new Paint(); // Color is set in onDraw(...)

		this.mDescriptionPaint = new Paint();
		this.mDescriptionPaint.setAntiAlias(true);
		this.mDescriptionPaint.setTextSize(fontSizePixels);
		this.mTitlePaint = new Paint();
		this.mTitlePaint.setTextSize(fontSizePixels);
		this.mTitlePaint.setFakeBoldText(true);
		this.mTitlePaint.setAntiAlias(true);
	}

	// ===========================================================
	// Getter & Setter
	// ===========================================================


	/**
	 * default is 3 pixels
	 * @param value
     */
	public void setDescriptionBoxPadding(int value ){
		DESCRIPTION_BOX_PADDING=value;
	}

	/**
	 * default 3
	 * @param value
     */
	public void setDescriptionBoxCornerWidth(int value){
		DESCRIPTION_BOX_CORNERWIDTH=value;
	}

	/**
	 * default is 2
	 * @param value
     */
	public void setDescriptionTitleExtraLineHeight(int value){
		DESCRIPTION_TITLE_EXTRA_LINE_HEIGHT=value;
	}

	/**
	 * default is a green like color
	 * @param value
     */
	public void setMarkerBackgroundColor(int value){
		mMarkerFocusedBackgroundColor=value;
	}
	public void setMarkerTitleForegroundColor(int value){
		mTitlePaint.setColor(value);
	}
	public void setMarkerDescriptionForegroundColor(int value){
		mDescriptionPaint.setColor(value);
	}

	/**
	 * default is 14
	 * @param value
     */
	public void setFontSize(int value){
		FONT_SIZE_DP=value;
		calculateDrawSettings();
	}

	/**
	 * in pixels, default is 600
	 * @param value
     */
	public void setDescriptionMaxWidth(int value){
		DESCRIPTION_MAXWIDTH=value;
		calculateDrawSettings();
	}

	/**
	 * default is 30
	 * @param value
     */
	public void setDescriptionLineHeight(int value){
		DESCRIPTION_LINE_HEIGHT=value;
		calculateDrawSettings();
	}

	public Item getFocusedItem() {
		if (this.mFocusedItemIndex == NOT_SET) {
			return null;
		}
		return this.mItemList.get(this.mFocusedItemIndex);
	}

	public void setFocusedItem(final int pIndex) {
		this.mFocusedItemIndex = pIndex;
	}

	public void unSetFocusedItem() {
		this.mFocusedItemIndex = NOT_SET;
	}

	public void setFocusedItem(final Item pItem) {
		final int indexFound = super.mItemList.indexOf(pItem);
		if (indexFound < 0) {
			throw new IllegalArgumentException();
		}

		this.setFocusedItem(indexFound);
	}

	public void setFocusItemsOnTap(final boolean doit) {
		this.mFocusItemsOnTap = doit;
	}

	// ===========================================================
	// Methods from SuperClass/Interfaces
	// ===========================================================

	@Override
	protected boolean onSingleTapUpHelper(final int index, final Item item, final MapView mapView) {
		if (this.mFocusItemsOnTap) {
			this.mFocusedItemIndex = index;
			mapView.postInvalidate();
		}
		return this.mOnItemGestureListener.onItemSingleTapUp(index, item);
	}

	private final Rect mRect = new Rect();

	@Override
	public void draw(final Canvas c, final MapView osmv, final boolean shadow) {

		super.draw(c, osmv, shadow);

		if (shadow) {
			return;
		}

		if (this.mFocusedItemIndex == NOT_SET) {
			return;
		}

		// this happens during shutdown
		if (super.mItemList==null)
			return;
		// get focused item's preferred marker & hotspot
		final Item focusedItem = super.mItemList.get(this.mFocusedItemIndex);
		Drawable markerFocusedBase = focusedItem.getMarker(OverlayItem.ITEM_STATE_FOCUSED_MASK);
		if (markerFocusedBase == null) {
			markerFocusedBase = this.mMarkerFocusedBase;
		}

		/* Calculate and set the bounds of the marker. */
		osmv.getProjection().toPixels(focusedItem.getPoint(), mFocusedScreenCoords);

		markerFocusedBase.copyBounds(mRect);
		mRect.offset(mFocusedScreenCoords.x, mFocusedScreenCoords.y);

		/* Strings of the OverlayItem, we need. */
		final String itemTitle = (focusedItem.getTitle() == null) ? UNKNOWN : focusedItem
				.getTitle();
		final String itemDescription = (focusedItem.getSnippet() == null) ? UNKNOWN : focusedItem
				.getSnippet();

		/*
		 * Store the width needed for each char in the description to a float array. This is pretty
		 * efficient.
		 */
		final float[] widths = new float[itemDescription.length()];
		this.mDescriptionPaint.getTextWidths(itemDescription, widths);

		final StringBuilder sb = new StringBuilder();
		int maxWidth = 0;
		int curLineWidth = 0;
		int lastStop = 0;
		int i;
		int lastwhitespace = 0;
		/*
		 * Loop through the charwidth array and harshly insert a linebreak, when the width gets
		 * bigger than DESCRIPTION_MAXWIDTH.
		 */
		for (i = 0; i < widths.length; i++) {
			if (!Character.isLetter(itemDescription.charAt(i))) {
				lastwhitespace = i;
			}

			final float charwidth = widths[i];

			if (curLineWidth + charwidth > DESCRIPTION_MAXWIDTH) {
				if (lastStop == lastwhitespace) {
					i--;
				} else {
					i = lastwhitespace;
				}

				sb.append(itemDescription.subSequence(lastStop, i));
				sb.append('\n');

				lastStop = i;
				maxWidth = Math.max(maxWidth, curLineWidth);
				curLineWidth = 0;
			}

			curLineWidth += charwidth;
		}
		/* Add the last line to the rest to the buffer. */
		if (i != lastStop) {
			final String rest = itemDescription.substring(lastStop, i);
			maxWidth = Math.max(maxWidth, (int) this.mDescriptionPaint.measureText(rest));
			sb.append(rest);
		}
		final String[] lines = sb.toString().split("\n");

		/*
		 * The title also needs to be taken into consideration for the width calculation.
		 */
		final int titleWidth = (int) this.mDescriptionPaint.measureText(itemTitle);

		maxWidth = Math.max(maxWidth, titleWidth);
		final int descWidth = Math.min(maxWidth, DESCRIPTION_MAXWIDTH);

		/* Calculate the bounds of the Description box that needs to be drawn. */
		final int descBoxLeft = mRect.left - descWidth / 2 - DESCRIPTION_BOX_PADDING
				+ mRect.width() / 2;
		final int descBoxRight = descBoxLeft + descWidth + 2 * DESCRIPTION_BOX_PADDING;
		final int descBoxBottom = mRect.top;
		final int descBoxTop = descBoxBottom - DESCRIPTION_TITLE_EXTRA_LINE_HEIGHT
				- (lines.length + 1) * DESCRIPTION_LINE_HEIGHT /* +1 because of the title. */
				- 2 * DESCRIPTION_BOX_PADDING;

		/* Twice draw a RoundRect, once in black with 1px as a small border. */
		this.mMarkerBackgroundPaint.setColor(Color.BLACK);
		c.drawRoundRect(new RectF(descBoxLeft - 1, descBoxTop - 1, descBoxRight + 1,
				descBoxBottom + 1), DESCRIPTION_BOX_CORNERWIDTH, DESCRIPTION_BOX_CORNERWIDTH,
				this.mDescriptionPaint);
		this.mMarkerBackgroundPaint.setColor(this.mMarkerFocusedBackgroundColor);
		c.drawRoundRect(new RectF(descBoxLeft, descBoxTop, descBoxRight, descBoxBottom),
				DESCRIPTION_BOX_CORNERWIDTH, DESCRIPTION_BOX_CORNERWIDTH,
				this.mMarkerBackgroundPaint);

		final int descLeft = descBoxLeft + DESCRIPTION_BOX_PADDING;
		int descTextLineBottom = descBoxBottom - DESCRIPTION_BOX_PADDING;

		/* Draw all the lines of the description. */
		for (int j = lines.length - 1; j >= 0; j--) {
			c.drawText(lines[j].trim(), descLeft, descTextLineBottom, this.mDescriptionPaint);
			descTextLineBottom -= DESCRIPTION_LINE_HEIGHT;
		}
		/* Draw the title. */
		c.drawText(itemTitle, descLeft, descTextLineBottom - DESCRIPTION_TITLE_EXTRA_LINE_HEIGHT,
				this.mTitlePaint);
		c.drawLine(descBoxLeft, descTextLineBottom, descBoxRight, descTextLineBottom,
				mDescriptionPaint);

		/*
		 * Finally draw the marker base. This is done in the end to make it look better.
		 */
		Overlay.drawAt(c, markerFocusedBase, mFocusedScreenCoords.x, mFocusedScreenCoords.y, false, osmv.getMapOrientation());
	}

	@Override
	public void onDetach(MapView mapView){
		super.onDetach(mapView);
		this.mContext=null;
	}

	// ===========================================================
	// Methods
	// ===========================================================

	// ===========================================================
	// Inner and Anonymous Classes
	// ===========================================================
}