vtm/vtm-android/src/org/oscim/android/MapScaleBar.java

274 lines
9.0 KiB
Java

/*
* Copyright 2010, 2011, 2012 mapsforge.org
* Copyright 2013 Hannes Janetzek
* Copyright 2016 devemux86
*
* This program is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.oscim.android;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import org.oscim.android.canvas.AndroidBitmap;
import org.oscim.core.MapPosition;
import org.oscim.core.MercatorProjection;
import org.oscim.event.Event;
import org.oscim.layers.Layer;
import org.oscim.map.Map;
import org.oscim.map.Map.UpdateListener;
import org.oscim.renderer.BitmapRenderer;
import java.util.HashMap;
/**
* A MapScaleBar displays the ratio of a distance on the map to the
* corresponding distance on the ground.
*/
public class MapScaleBar extends Layer implements UpdateListener {
private static final int BITMAP_HEIGHT = 64;
private static final int BITMAP_WIDTH = 128;
private static final double LATITUDE_REDRAW_THRESHOLD = 0.2;
// private static final int MARGIN_BOTTOM = 5;
// private static final int MARGIN_LEFT = 5;
private static final double METER_FOOT_RATIO = 0.3048;
private static final int ONE_KILOMETER = 1000;
private static final int ONE_MILE = 5280;
private static final Paint SCALE_BAR = new Paint(Paint.ANTI_ALIAS_FLAG);
private static final Paint SCALE_BAR_STROKE = new Paint(Paint.ANTI_ALIAS_FLAG);
private static final Paint SCALE_TEXT = new Paint(Paint.ANTI_ALIAS_FLAG);
private static final Paint SCALE_TEXT_STROKE = new Paint(Paint.ANTI_ALIAS_FLAG);
private static final int[] SCALE_BAR_VALUES_IMPERIAL = {
26400000, 10560000, 5280000,
2640000, 1056000, 528000,
264000, 105600, 52800, 26400,
10560, 5280, 2000, 1000, 500,
200, 100, 50, 20,
10, 5, 2, 1};
private static final int[] SCALE_BAR_VALUES_METRIC = {
10000000, 5000000, 2000000, 1000000,
500000, 200000, 100000, 50000,
20000, 10000, 5000, 2000, 1000,
500, 200, 100, 50, 20, 10, 5, 2, 1};
private boolean mImperialUnits;
private final Canvas mMapScaleCanvas;
private boolean mRedrawNeeded;
private double mPrevLatitude = -1;
private final double mPrevScale = -1;
private final HashMap<TextField, String> mTextFields;
private final Bitmap mBitmap;
// passed to BitmapRenderer - need to sync on this object.
private final AndroidBitmap mLayerBitmap;
private final BitmapRenderer mBitmapLayer;
public MapScaleBar(MapView map) {
super(map.map());
mBitmap = Bitmap.createBitmap(BITMAP_WIDTH,
BITMAP_HEIGHT,
Bitmap.Config.ARGB_8888);
mMapScaleCanvas = new Canvas(mBitmap);
mTextFields = new HashMap<TextField, String>();
setDefaultTexts();
configurePaints();
mRedrawNeeded = true;
mRenderer = mBitmapLayer = new BitmapRenderer();
mLayerBitmap = new AndroidBitmap(mBitmap);
mBitmapLayer.setBitmap(mLayerBitmap, BITMAP_WIDTH, BITMAP_HEIGHT);
}
@Override
public void onMapEvent(Event e, MapPosition mapPosition) {
if (e == Map.UPDATE_EVENT)
return;
double latitude = MercatorProjection.toLatitude(mapPosition.y);
if (!mRedrawNeeded) {
double scaleDiff = mPrevScale / mapPosition.scale;
if (scaleDiff < 1.1 && scaleDiff > 0.9) {
double latitudeDiff = Math.abs(mPrevLatitude - latitude);
if (latitudeDiff < LATITUDE_REDRAW_THRESHOLD)
return;
}
}
mPrevLatitude = latitude;
double groundResolution = MercatorProjection
.groundResolution(latitude, mapPosition.scale);
int[] scaleBarValues;
if (mImperialUnits) {
groundResolution = groundResolution / METER_FOOT_RATIO;
scaleBarValues = SCALE_BAR_VALUES_IMPERIAL;
} else {
scaleBarValues = SCALE_BAR_VALUES_METRIC;
}
float scaleBarLength = 0;
int mapScaleValue = 0;
for (int i = 0; i < scaleBarValues.length; ++i) {
mapScaleValue = scaleBarValues[i];
scaleBarLength = mapScaleValue / (float) groundResolution;
if (scaleBarLength < (BITMAP_WIDTH - 10)) {
break;
}
}
synchronized (mLayerBitmap) {
redrawMapScaleBitmap(scaleBarLength, mapScaleValue);
}
mBitmapLayer.updateBitmap();
mRedrawNeeded = false;
}
/**
* @return true if imperial units are used, false otherwise.
*/
public boolean isImperialUnits() {
return mImperialUnits;
}
/**
* @param imperialUnits true if imperial units should be used rather than metric
* units.
*/
public void setImperialUnits(boolean imperialUnits) {
mImperialUnits = imperialUnits;
mRedrawNeeded = true;
}
/**
* Overrides the specified text field with the given string.
*
* @param textField the text field to override.
* @param value the new value of the text field.
*/
public void setText(TextField textField, String value) {
mTextFields.put(textField, value);
mRedrawNeeded = true;
}
private void drawScaleBar(float scaleBarLength, Paint paint) {
mMapScaleCanvas.drawLine(7, 25, scaleBarLength + 3, 25, paint);
mMapScaleCanvas.drawLine(5, 10, 5, 40, paint);
mMapScaleCanvas.drawLine(scaleBarLength + 5, 10, scaleBarLength + 5, 40, paint);
}
private void drawScaleText(int scaleValue, String unitSymbol, Paint paint) {
mMapScaleCanvas.drawText(scaleValue + unitSymbol, 12, 18, paint);
}
/**
* Redraws the map scale bitmap with the given parameters.
*
* @param scaleBarLength the length of the map scale bar in pixels.
* @param mapScaleValue the map scale value in meters.
*/
private void redrawMapScaleBitmap(float scaleBarLength, int mapScaleValue) {
mBitmap.eraseColor(Color.TRANSPARENT);
// draw the scale bar
drawScaleBar(scaleBarLength, SCALE_BAR_STROKE);
drawScaleBar(scaleBarLength, SCALE_BAR);
int scaleValue;
String unitSymbol;
if (mImperialUnits) {
if (mapScaleValue < ONE_MILE) {
scaleValue = mapScaleValue;
unitSymbol = mTextFields.get(TextField.FOOT);
} else {
scaleValue = mapScaleValue / ONE_MILE;
unitSymbol = mTextFields.get(TextField.MILE);
}
} else {
if (mapScaleValue < ONE_KILOMETER) {
scaleValue = mapScaleValue;
unitSymbol = mTextFields.get(TextField.METER);
} else {
scaleValue = mapScaleValue / ONE_KILOMETER;
unitSymbol = mTextFields.get(TextField.KILOMETER);
}
}
// draw the scale text
drawScaleText(scaleValue, unitSymbol, SCALE_TEXT_STROKE);
drawScaleText(scaleValue, unitSymbol, SCALE_TEXT);
}
private void setDefaultTexts() {
mTextFields.put(TextField.FOOT, " ft");
mTextFields.put(TextField.MILE, " mi");
mTextFields.put(TextField.METER, " m");
mTextFields.put(TextField.KILOMETER, " km");
}
private static void configurePaints() {
SCALE_BAR.setStrokeWidth(2);
SCALE_BAR.setStrokeCap(Paint.Cap.SQUARE);
SCALE_BAR.setColor(Color.BLACK);
SCALE_BAR_STROKE.setStrokeWidth(5);
SCALE_BAR_STROKE.setStrokeCap(Paint.Cap.SQUARE);
SCALE_BAR_STROKE.setColor(Color.WHITE);
SCALE_TEXT.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
SCALE_TEXT.setTextSize(17);
SCALE_TEXT.setColor(Color.BLACK);
SCALE_TEXT_STROKE.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
SCALE_TEXT_STROKE.setStyle(Paint.Style.STROKE);
SCALE_TEXT_STROKE.setColor(Color.WHITE);
SCALE_TEXT_STROKE.setStrokeWidth(2);
SCALE_TEXT_STROKE.setTextSize(17);
}
/**
* Enumeration of all text fields.
*/
public enum TextField {
/**
* Unit symbol for one foot.
*/
FOOT,
/**
* Unit symbol for one kilometer.
*/
KILOMETER,
/**
* Unit symbol for one meter.
*/
METER,
/**
* Unit symbol for one mile.
*/
MILE;
}
}