現在のズーム レベルに応じて画面に現在の長さを表示するマップ スケールを追加するのに苦労しています。使用する定義済みのクラスが存在する可能性があると感じていますが、手がかりがありません...? 私はたくさん検索しましたが、何も見つかりません。
どんな助けでも大歓迎です=）
// アレックス
質問する
7258 次
2 に答える
6
よし、今わかった！Luis answer は私を大いに助け、OpenStreetMap も助けてくれました。これが私が思いついたものです：
<your.own.package.path>;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Picture;
import android.graphics.Rect;
import android.location.Location;
import android.util.Log;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.Projection;
import com.iqqn.uppgift5.GameMapActivity;
public class ScaleBarOverlay extends Overlay{
// ===========================================================
// Fields
// ===========================================================
// Defaults
boolean enabled = true;
float xOffset = 10;
float yOffset = 10;
float lineWidth = 2;
int textSize = 12;
boolean imperial = false;
boolean nautical = false;
boolean latitudeBar = true;
boolean longitudeBar = false;
// Internal
protected final MapView mapView;
protected final GameMapActivity master;
private Context context;
protected final Picture scaleBarPicture = new Picture();
private final Matrix scaleBarMatrix = new Matrix();
private int lastZoomLevel = -1;
float xdpi;
float ydpi;
int screenWidth;
int screenHeight;
// ===========================================================
// Constructors
// ===========================================================
public ScaleBarOverlay(Context _context, GameMapActivity master, MapView mapView) {
super();
this.master = master;
this.context = _context;
this.mapView = mapView;
xdpi = this.context.getResources().getDisplayMetrics().xdpi;
ydpi = this.context.getResources().getDisplayMetrics().ydpi;
screenWidth = this.context.getResources().getDisplayMetrics().widthPixels;
screenHeight = this.context.getResources().getDisplayMetrics().heightPixels;
}
// ===========================================================
// Getter & Setter
// ===========================================================
/**
* @return the enabled
*/
public boolean isEnabled() {
return enabled;
}
/**
* @param enabled the enabled to set
*/
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
/**
* @return the lineWidth
*/
public float getLineWidth() {
return lineWidth;
}
/**
* @param lineWidth the lineWidth to set
*/
public void setLineWidth(float lineWidth) {
this.lineWidth = lineWidth;
}
/**
* @return the imperial
*/
public boolean isImperial() {
return imperial;
}
/**
* @param imperial the imperial to set
*/
public void setImperial() {
this.imperial = true;
this.nautical = false;
createScaleBarPicture();
}
/**
* @return the nautical
*/
public boolean isNautical() {
return nautical;
}
/**
* @param nautical the nautical to set
*/
public void setNautical() {
this.nautical = true;
this.imperial = false;
createScaleBarPicture();
}
public void setMetric() {
this.nautical = false;
this.imperial = false;
createScaleBarPicture();
}
public void drawLatitudeScale(boolean latitude) {
this.latitudeBar = latitude;
}
public void drawLongitudeScale(boolean longitude) {
this.longitudeBar = longitude;
}
@Override
public void draw(Canvas canvas, MapView localMapView, boolean shadow) {
if (this.enabled) {
// Draw the overlay
if (shadow == false) {
final int zoomLevel = localMapView.getZoomLevel();
if (zoomLevel != lastZoomLevel) {
lastZoomLevel = zoomLevel;
createScaleBarPicture();
}
this.scaleBarMatrix.setTranslate(-1 * (scaleBarPicture.getWidth() / 2 - 0.5f), -1 * (scaleBarPicture.getHeight() / 2 - 0.5f));
this.scaleBarMatrix.postTranslate(xdpi/2, ydpi/2 + canvas.getHeight()-50);
canvas.save();
canvas.setMatrix(scaleBarMatrix);
canvas.drawPicture(scaleBarPicture);
canvas.restore();
}
}
}
// ===========================================================
// Methods
// ===========================================================
public void disableScaleBar() {
this.enabled = false;
}
public boolean enableScaleBar() {
return this.enabled = true;
}
private void createScaleBarPicture() {
// We want the scale bar to be as long as the closest round-number miles/kilometers
// to 1-inch at the latitude at the current center of the screen.
Projection projection = mapView.getProjection();
if (projection == null) {
return;
}
Location locationP1 = new Location("ScaleBar location p1");
Location locationP2 = new Location("ScaleBar location p2");
// Two points, 1-inch apart in x/latitude, centered on screen
GeoPoint p1 = projection.fromPixels((int) ((screenWidth / 2) - (xdpi / 2)), screenHeight/2);
GeoPoint p2 = projection.fromPixels((int) ((screenWidth / 2) + (xdpi / 2)), screenHeight/2);
locationP1.setLatitude(p1.getLatitudeE6()/1E6);
locationP2.setLatitude(p2.getLatitudeE6()/1E6);
locationP1.setLongitude(p1.getLongitudeE6()/1E6);
locationP2.setLongitude(p2.getLongitudeE6()/1E6);
float xMetersPerInch = locationP1.distanceTo(locationP2);
p1 = projection.fromPixels(screenWidth/2, (int) ((screenHeight / 2) - (ydpi / 2)));
p2 = projection.fromPixels(screenWidth/2, (int) ((screenHeight / 2) + (ydpi / 2)));
locationP1.setLatitude(p1.getLatitudeE6()/1E6);
locationP2.setLatitude(p2.getLatitudeE6()/1E6);
locationP1.setLongitude(p1.getLongitudeE6()/1E6);
locationP2.setLongitude(p2.getLongitudeE6()/1E6);
float yMetersPerInch = locationP1.distanceTo(locationP2);
final Paint barPaint = new Paint();
barPaint.setColor(Color.BLACK);
barPaint.setAntiAlias(true);
barPaint.setStyle(Style.FILL);
barPaint.setAlpha(255);
final Paint textPaint = new Paint();
textPaint.setColor(Color.BLACK);
textPaint.setAntiAlias(true);
textPaint.setStyle(Style.FILL);
textPaint.setAlpha(255);
textPaint.setTextSize(textSize);
final Canvas canvas = scaleBarPicture.beginRecording((int)xdpi, (int)ydpi);
if (latitudeBar) {
String xMsg = scaleBarLengthText(xMetersPerInch, imperial, nautical);
Rect xTextRect = new Rect();
textPaint.getTextBounds(xMsg, 0, xMsg.length(), xTextRect);
int textSpacing = (int)(xTextRect.height() / 5.0);
canvas.drawRect(xOffset, yOffset, xOffset + xdpi, yOffset + lineWidth, barPaint);
canvas.drawRect(xOffset + xdpi, yOffset, xOffset + xdpi + lineWidth, yOffset + xTextRect.height() + lineWidth + textSpacing, barPaint);
if (!longitudeBar) {
canvas.drawRect(xOffset, yOffset, xOffset + lineWidth, yOffset + xTextRect.height() + lineWidth + textSpacing, barPaint);
}
canvas.drawText(xMsg, (xOffset + xdpi/2 - xTextRect.width()/2), (yOffset + xTextRect.height() + lineWidth + textSpacing), textPaint);
}
if (longitudeBar) {
String yMsg = scaleBarLengthText(yMetersPerInch, imperial, nautical);
Rect yTextRect = new Rect();
textPaint.getTextBounds(yMsg, 0, yMsg.length(), yTextRect);
int textSpacing = (int)(yTextRect.height() / 5.0);
canvas.drawRect(xOffset, yOffset, xOffset + lineWidth, yOffset + ydpi, barPaint);
canvas.drawRect(xOffset, yOffset + ydpi, xOffset + yTextRect.height() + lineWidth + textSpacing, yOffset + ydpi + lineWidth, barPaint);
if (! latitudeBar) {
canvas.drawRect(xOffset, yOffset, xOffset + yTextRect.height() + lineWidth + textSpacing, yOffset + lineWidth, barPaint);
}
float x = xOffset + yTextRect.height() + lineWidth + textSpacing;
float y = yOffset + ydpi/2 + yTextRect.width()/2;
canvas.rotate(-90, x, y);
canvas.drawText(yMsg, x, y + textSpacing, textPaint);
}
scaleBarPicture.endRecording();
}
private String scaleBarLengthText(float meters, boolean imperial, boolean nautical) {
if (this.imperial) {
if (meters >= 1609.344) {
return (meters / 1609.344) + "mi";
} else if (meters >= 1609.344/10) {
return ((meters / 160.9344) / 10.0) + "mi";
} else {
return (meters * 3.2808399) + "ft";
}
} else if (this.nautical) {
if (meters >= 1852) {
return ((meters / 1852)) + "nm";
} else if (meters >= 1852/10) {
return (((meters / 185.2)) / 10.0) + "nm";
} else {
return ((meters * 3.2808399)) + "ft";
}
} else {
if (meters >= 1000) {
return ((meters / 1000)) + "km";
} else if (meters > 100) {
return ((meters / 100.0) / 10.0) + "km";
} else {
return meters + "m";
}
}
}
@Override
public boolean onTap(GeoPoint point, MapView mapView) {
// Do not react to screen taps.
return false;
}
}
onCreate() で次のように使用します。
...
scaleBarOverlay = new ScaleBarOverlay(this.getBaseContext(), this, myMapView);
List<Overlay> overlays = myMapView.getOverlays();
// Add scale bar overlay
scaleBarOverlay.setMetric();
overlays.add(scaleBarOverlay);
...
これが誰にとっても役立つことを願っています =) これは API レベル 7 以降で機能します。ただし、API レベル 14+ でテストしたことはありません。また、キャンバスで絵を描くように、ハードウェア アクセラレーション機能が「機能しない」ことを知っています。でも、録音でいいと思います。
ありがとうルイス！
// アレクサンダー
于 2012-10-19T12:43:07.543 に答える
3
私の知る限り、それを行うための事前定義されたクラスはありません。
可能性の 1 つは、緯度に応じて変化する現在の経度スパンをチェックするオーバーレイを作成し、正しいサイズで縮尺を描画することです。
以下に、その方法の例を示します。
スケールバー オーバーレイ
public class CopyOfScaleBarOverlay extends Overlay {
private static final String STR_M = "m";
private static final String STR_KM = "km";
//Constants
private static float scaleBarProportion = 0.25f;
private float cMarginLeft=4;
private float cLineTopSize=8;
private float cMarginTop=6;
private float cMarginBottom=2;
private float cTextSize=12;
private float distanceFromBottom=100;
//instantiation
private Context context;
private Paint paintLine, paintText, paintRectangle;
private Location l0;
private Location l1;
private float ds;
private int width, height, pi;
private float marginLeft, marginTop, marginBottom, lineTopSize;
private String unit;
public CopyOfScaleBarOverlay(Context context){
super();
this.context=context;
paintText= new TextPaint();
paintText.setARGB(180, 0, 0, 0);
paintText.setAntiAlias(true);
paintText.setTextAlign(Align.CENTER);
paintRectangle = new Paint();
paintRectangle.setARGB(80,255,255,255);
paintRectangle.setAntiAlias(true);
paintLine = new Paint();
paintLine.setARGB(180, 0, 0, 0);
paintLine.setAntiAlias(true);
l0 = new Location("none");
l1 = new Location("none");
ds=this.context.getApplicationContext().getResources().getDisplayMetrics().density;
width=this.context.getApplicationContext().getResources().getDisplayMetrics().widthPixels;
height=this.context.getApplicationContext().getResources().getDisplayMetrics().heightPixels;
pi = (int) (height - distanceFromBottom *ds);
marginLeft=cMarginLeft*ds;
lineTopSize=cLineTopSize*ds;
marginTop=cMarginTop*ds;
marginBottom=cMarginBottom*ds;
}
@Override
public void draw(Canvas canvas, MapView mapview, boolean shadow) {
super.draw(canvas, mapview, shadow);
if(mapview.getZoomLevel() > 1){
//Calculate scale bar size and units
GeoPoint g0 = mapview.getProjection().fromPixels(0, height/2);
GeoPoint g1 = mapview.getProjection().fromPixels(width, height/2);
l0.setLatitude(g0.getLatitudeE6()/1E6);
l0.setLongitude(g0.getLongitudeE6()/1E6);
l1.setLatitude(g1.getLatitudeE6()/1E6);
l1.setLongitude(g1.getLongitudeE6()/1E6);
float d01=l0.distanceTo(l1);
float d02=d01*scaleBarProportion;
// multiply d02 by a unit conversion factor if needed
float cd02;
if(d02 > 1000){
unit = STR_KM;
cd02 = d02 / 1000;
} else{
unit = STR_M;
cd02 = d02;
}
int i=1;
do{
i *=10;
}while (i <= cd02);
i/=10;
float dcd02=(int)(cd02/i)*i;
float bs=dcd02*width/d01*d02/cd02;
String text=String.format("%.0f %s", dcd02, unit);
paintText.setTextSize(cTextSize * ds);
float text_x_size=paintText.measureText(text);
float x_size = bs + text_x_size/2 + 2*marginLeft;
//Draw rectangle
canvas.drawRect(0,pi,x_size,pi+marginTop+paintText.getFontSpacing()+marginBottom, paintRectangle);
//Draw line
canvas.drawLine(marginLeft, pi+marginTop, marginLeft + bs, pi+marginTop, paintLine);
//Draw line tops
canvas.drawLine(marginLeft, pi+marginTop - lineTopSize/2, marginLeft, pi+marginTop + lineTopSize/2, paintLine);
canvas.drawLine(marginLeft +bs, pi+marginTop - lineTopSize/2, marginLeft+bs, pi+marginTop + lineTopSize/2, paintLine);
//Draw line midle
canvas.drawLine(marginLeft + bs/2, pi+marginTop - lineTopSize/3, marginLeft + bs/2, pi+marginTop + lineTopSize/3, paintLine);
//Draw line quarters
canvas.drawLine(marginLeft + bs/4, pi+marginTop - lineTopSize/4, marginLeft + bs/4, pi+marginTop + lineTopSize/4, paintLine);
canvas.drawLine(marginLeft + 3*bs/4, pi+marginTop - lineTopSize/4, marginLeft + 3*bs/4, pi+marginTop + lineTopSize/4, paintLine);
//Draw text
canvas.drawText(text, marginLeft +bs, pi+marginTop+paintText.getFontSpacing(), paintText);
}
}
}
使用するには
を拡張するアクティビティでMapActivity、次を追加します。
mapView.getOverlays().add(new CopyOfScaleBarOverlay(this));
ノート
この例では、メートル単位を使用しています。別の単位系を使用するd02には、上記のコードに単位変換係数を掛けて、文字列を単位名で調整します。
楽しめ。
于 2012-10-19T00:16:21.247 に答える