QT5 minimum map using QML

[alexfish]

Hi Joe

have a file saved as gps.txt
content
51.13333:1.3

in code below change path where gps.txt is


 import QtQuick 2.0
 import QtQuick.Window 2.0
 import QtLocation 5.15
 import QtPositioning 5.15

 Window {
     width: 512
     height: 512
     visible: true

     Plugin {
         id: osmPlugin
         name: "osm"
     }

     Map {
id:mapview
         anchors.fill: parent
         plugin: osmPlugin
         center: QtPositioning.coordinate(59.91, 10.75) // Oslo
         zoomLevel: 14
     }

MouseArea {
id: mouseArea
      property variant lastCoordinate
anchors.fill: parent
acceptedButtons: Qt.LeftButton | Qt.RightButton


onPressAndHold:{
var xhr = new XMLHttpRequest;
xhr.open("GET", "/home/pi/gps.txt");
xhr.onreadystatechange = function() {
    if (xhr.readyState == XMLHttpRequest.DONE) {
        var response = xhr.responseText.split(':');

console.log(response[0]);
console.log(response[1]);

var lat = parseFloat(response[0]);
var lon = parseFloat(response[1]);

mapview.center = QtPositioning.coordinate(lat,lon);
var coordinate = mapview.toCoordinate(Qt.point(mouse.x,mouse.y));

console.log(coordinate);

   }
};
xhr.send();


               }
}
}


thinking the qtmm to gps data can be used as per your demo code
+ here
further reads can be written to a file ,

TODO :
Find a callback feature in the qml to suit situation: ?

Interesting I just found some bits relating to the engine an qml maps

HERE

did a qmake & make
result see picky :: follow the yellow brick road:
BR
Alex

Attachments:

[bigbass]

hello Alex


good to see your progress I will
give it a try
and for the link I will try to port it
that would be good for reading in a log file
and less code to sort out


LINUX
I was and still am deep into getting this part working for linux
runebook.dev/en/docs/qt/qtremoteobjects-index


ANDROID
in android I have it working completely 100%
because its a lot easier built in gps and the permission to use
location connects to the inbuilt gpsd through sockets

http://127.0.0.1:11330/main/0/storage/emulated/0/your_location_gps.html

maybe the port changes but that works for where I am

sourceforge.net/p/bacon-qt5/wiki/your_location_gps/


working on making something close to that for linux

Joe

[alexfish]

Hi Joe

should be no need to write to file

can use the three functions on the QT side serial wifi, local , like gpsd linux , here gpsmm then Android m you have shown

You have shown all of these bits on different threads + the gpsmm here

as mentioned I was on the hunt for a specific callback ,was lucky to fined that demo.

so here we get the qml object then pass the changes of gps position using slot to the qml map ,
that is the qml callback IE notify position changed .... viola

Now can Baconise QT maps until the cows come home

BR
Alex

PS :looking forward to your next demo + very willing to test

[bigbass]

just on the light side of things
while researching sockets it sent me here
doc.qt.io/qt-6.2/qremoteobjectnode.html#heartbeatInterval-prop

The heartbeat (only helpful for socket connections) will periodically send a message to connected nodes to detect whether the connection was disrupted. Qt Remote Objects will try to reconnect automatically if it detects a dropped connection. This function can help with that detection since the client will only detect that the server is unavailable when it tries to send data.

A value of 0 (the default) will disable the heartbeat.

and couldn't help but think about what porting this would say


FUNCTION heartbeatIntervalChanged(int heartbeatInterval) TYPE int

IF heartbeatInterval == 0 THEN
PRINT " You are dead but you won't see this message"
ELSE
PRINT " You get another chance "
RETURN TRUE
END IF
END FUNCTION

CALL heartbeatIntervalChanged(1)



sorry I was reading to much
and needed a break

Joe

[alexfish]

Sept 26, 2022 17:37:22 GMT 1 bigbass said:

just on the light side of things
while researching sockets it sent me here
doc.qt.io/qt-6.2/qremoteobjectnode.html#heartbeatInterval-prop

The heartbeat (only helpful for socket connections) will periodically send a message to connected nodes to detect whether the connection was disrupted. Qt Remote Objects will try to reconnect automatically if it detects a dropped connection. This function can help with that detection since the client will only detect that the server is unavailable when it tries to send data.

A value of 0 (the default) will disable the heartbeat.

and couldn't help but think about what porting this would say


FUNCTION heartbeatIntervalChanged(int heartbeatInterval) TYPE int

IF heartbeatInterval == 0 THEN
PRINT " You are dead but you won't see this message"
ELSE
PRINT " You get another chance "
RETURN TRUE
END IF
END FUNCTION

CALL heartbeatIntervalChanged(1)



sorry I was reading to much
and needed a break

Joe

in a lighthearted way ..

one thing I know 'inheritance' can be very taxing

FUNCTION inheritanceChanged(int inheritanceInterval) TYPE int

IF inheritanceInterval == 0 THEN
PRINT " You are dead but you won't see this message"
ELSE
PRINT "Pay More tax "
RETURN TRUE
END IF
END FUNCTION

BR
Alex

[alexfish]

Hi Joe

have managed to get the CLASS MarkerManager: public QObject in

it complies : needs more work

1.remove file reads etc
2. sort timer
3. add the oneshot read the gpsd get the data and transfer to
4. add the marker function to qml file + redo the callback bits

hope this helps

item 3 & 4 relate main.moc ... total stuck
thinking need to look further at this .pro & qmake & make

Now my grey matter is starting to FRY...ee
a make file 10 * size of prog
total stuck stuck stuck.

BR
Alex

Attachments:

qtqml2.bac.bz2 (1.23 KB)

[alexfish]

Did Further reading
HERE

esp note engine

BR
Alex

[bigbass]

Hello Alex
'inheritance' can be very taxing

Thanks I looked at your code
and haven't solved all the problems on that list yet
I decide to take a step backward and go here
to clear my mind and go a step at a time as you know
maps are complex

doc-snapshots.qt.io/qt-mobility/tutorials-mapsdemo-part1.html

in the past
I was able to use CLASS in fltk and connect back to the class and communicate

and remember I had to remove all the dot member code to use the c++ "new" then convert to using -> something like this
in QT5


DECLARE app TYPE QGuiApplication*
DECLARE engine TYPE QQmlApplicationEngine*


#MEMORY fix for bacon
then do this notice the word new
app = new QGuiApplication(argc, argv)
engine = new QQmlApplicationEngine()

then see it works here with the arrow operator ->
engine->load(QUrl(QStringLiteral("main2.qml")))
app->exec()


first step make sure you get all the headers !

Joe

[alexfish]

Hi Joe

will look closer at those bits

looking in a logical sense of what i posted

somewhere in
engine->load(QUrl(QStringLiteral("./main.qml")))

there must be a get context something or set
get blagh make slot foo
engine has the main.qml object

engine->blagh .slot. set(foo)

or I am looking at this in the wrong context

esp when looking at this from the docs


int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    MapsWidget w;
    w.show();

    QList<QString> providers = QGeoServiceProvider::availableServiceProviders();
    QGeoServiceProvider *serviceProvider = new QGeoServiceProvider(providers[0]);

    w.initialize(serviceProvider->mappingManager());

    return a.exec();
}

suppose here looking at the w.blagh* bits
with pointer becomes like w-show(); and w->initialize

slotwise just a thought

w->center(lat,lon);

added:: osm maps c

at the timeout callback have
IF tracking THEN
LOCAL maps TYPE OsmGpsMap *
maps = OSM_GPS_MAP(user_data)
osm_gps_map_gps_add (maps, NMEA.LAT,NMEA.LON,0)
osm_gps_map_set_center((gpointer) maps,  NMEA.LAT,  NMEA.LON)
END IF

compare qt maps doc
class MainWindow : public QMainWindow
{
private:
    QGeoPositionInfoSource *positionSource;

private slots:
    // slot to receive updates
    void updateMyPosition(QGeoPositionInfo info);
};


context wise qml map has marker (generally a png)
osm has
OsmGpsMapImage * osm_gps_map_image_add ()

BR
Alex

[alexfish]

Hi Joe

tried timer in the main.qml

source doc HERE
not the correct slot : tried position changed = segfault , so possible look further into the properties

so for now have read external file RE: the gps.txt

BR
Alex

the code for main.qml


import QtQuick 2.0
 import QtQuick.Window 2.0
 import QtLocation 5.15
 import QtPositioning 5.15

 Window {
     width: 512
     height: 512
     visible: true

     Plugin {
         id: osmPlugin
         name: "osm"
     }

     Map {
id:mapview
         anchors.fill: parent
         plugin: osmPlugin
         center: QtPositioning.coordinate(59.91, 10.75) // Oslo
         zoomLevel: 14
       MapQuickItem{
           id: marker
           anchorPoint.x: marker.width / 4
           anchorPoint.y: marker.height
           coordinate: manager.position

           }

     }

  Text {
      id: foo
      font.pointSize: 12
      function set() {
          foo.text = Date()
console.log(foo.text)
var xhr = new XMLHttpRequest;
xhr.open("GET", "/home/pi/gps.txt");
xhr.onreadystatechange = function() {
    if (xhr.readyState == XMLHttpRequest.DONE) {
        var response = xhr.responseText.split(':');

console.log(response[0]);
console.log(response[1]);

var lat = parseFloat(response[0]);
var lon = parseFloat(response[1]);
mapview.center = QtPositioning.coordinate(lat,lon);
   }
};
xhr.send();


      }
  }


  Timer {
      id: textTimer
      interval: 1000
      repeat: true
      running: true
      triggeredOnStart: true
      onTriggered: foo.set()
  }


MouseArea {
id: mouseArea
      property variant lastCoordinate
anchors.fill: parent
acceptedButtons: Qt.LeftButton | Qt.RightButton


onPressAndHold:{
var coordinate = mapview.toCoordinate(Qt.point(mouse.x,mouse.y));

console.log(coordinate);



               }
}
}


to suppress file io errors
add
qputenv("QML_XHR_ALLOW_FILE_READ", QByteArray("1"))

to the main QT code
Added Text with concat postion


  Text {
id: foo
font.pointSize: 16
font.bold:true
function set() {
     
          //foo.text=Date();
var xhr = new XMLHttpRequest;
xhr.open("GET", "/home/pi/gps.txt");
xhr.onreadystatechange = function() {
    if (xhr.readyState == XMLHttpRequest.DONE) {
        var response = xhr.responseText.split(':');

console.log(response[0]);
console.log(response[1]);

var lat = parseFloat(response[0]);
var lon = parseFloat(response[1]);
let result = response[0].concat(" : ",response[1]);
foo.text=result;
mapview.center = QtPositioning.coordinate(lat,lon);
   }
};
xhr.send();


[alexfish]

Hi Joe

the bacon code for the writing to file

' example  gpsd client
' original code source here https://gpsd.io/gpsd-client-example-code.html
' ported to bacon by bigbass then simplified readability with macros
' modified to compile in c++


PRAGMA INCLUDE <string.h> <stdio.h>  <libgpsmm.h> <math.h>  <iostream>
PRAGMA COMPILER c++
PRAGMA LDFLAGS  -Wall -pedantic -pthread -lgps    
PRAGMA OPTIONS -Wno-deprecated -Wno-writable-strings
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith

OPTION PARSE FALSE

CONST MODE_STR_NUM = 4

'add 6 zeros automatically to the seconds you want to wait
'dev is device or data the ADDRESS is handled in the macro to keep it easy

DEF FN GPSOPEN(ip,port,dev) =   gps_open(ip, port, &dev)
DEF FN STREAM(dev,op) = (void) gps_stream(&dev, op, NULL)
DEF FN WAITFOR(dev,timesec) =   gps_waiting(&dev, timesec * 1000000)
DEF FN GPSREAD(dev) = gps_read(&dev, NULL, 0)
DEF FN GPSCLOSE(dev) =  (void)gps_close(&dev)


DECLARE mode_str[MODE_STR_NUM]= { \
   "n/a", \
   "None", \
   "2D", \
   "3D" \
} TYPE static char *



   struct gps_data_t gps_data

   ' ip ,port ,device or data
   IF (0 ISNOT GPSOPEN("localhost", "2947", gps_data)) THEN
       EPRINT "Open error.  Bye, bye"
       END
   END IF

   STREAM(gps_data,WATCH_ENABLE | WATCH_JSON)

   'wait for 5 seconds
   WHILE (WAITFOR(gps_data,5))
       IF (-1 == GPSREAD(gps_data)) THEN
           EPRINT "Read error.  Bye, bye"
           BREAK
       END IF

       IF (MODE_SET ISNOT (MODE_SET & gps_data.set)) THEN
           'did not even get mode, nothing to see here
           CONTINUE
       END IF

       IF (0 > gps_data.fix.mode OR  \
           MODE_STR_NUM <= gps_data.fix.mode) THEN
           gps_data.fix.mode = 0
       END IF


       'PRINT "Fix mode: ", mode_str[gps_data.fix.mode], \
      ' "Time: ",  gps_data.fix.mode FORMAT  "%s %s %s  %d"


       IF (TIME_SET == (TIME_SET & gps_data.set)) THEN
           ' not 32 bit safe

          ' PRINT gps_data.fix.time.tv_sec, \
            '     gps_data.fix.time.tv_nsec FORMAT "%ld.%09ld "


       ELSE
           PRINT "n/a "
       END IF


       IF (isfinite(gps_data.fix.latitude) && \
           isfinite(gps_data.fix.longitude)) THEN
           'Display data from the GPS receiver if valid.
           PRINT gps_data.fix.latitude, gps_data.fix.longitude FORMAT  "%.6f:%.6f\n"  
           gps$ = STR$( gps_data.fix.latitude) &  ":" & STR$( gps_data.fix.longitude)
           OPEN "gps.txt" FOR WRITING AS myfile
           WRITELN gps$ TO myfile
           CLOSE FILE myfile
       ELSE
           PRINT "Lat n/a Lon n/a\n"
       END IF

   WEND

   ' When you are done...
    STREAM(gps_data,WATCH_DISABLE)
    GPSCLOSE(gps_data)

does it work :: Yes

that will do for now : from my side
need to finish navigation 2 bits , same time will add a qmlmap tiles to qmlseamap tiles converter

BR
Alex

[alexfish]

Hi Joe
have updated main.qml

have fun
+
BR
Alex

Attachments:

main.qml.bz2 (1.78 KB)

[bigbass]

Hey Alex thats it!

reading on the qml dynamic side of things
simplifies the code

for all practical reasons thats a demo
congratulations great job!

of course we will add in some candy
and maybe or not later do it with sockets


P.S you might have to wash your hands well
and get that fishy smell off after using that javascript
javascript.info/xmlhttprequest

thanks
Joe

[alexfish]

Hi Joe

I had a chat with one of my boys , eyes just roll , and mumbled we use 'curl' or blag it
did not get a lot of the howto , possible previous interaction about me and that word J

in theory one should be able to make a plugin for readfile .. beyond my scope

so... putting the bits together

for your info + further r&d see archive dynamic2 , be aware there is a main.qml in the folder

Should not see any stinking fish in the terminal that's the 'blag it'

also note the use of ID: * and how those are used

can give some eyecandy by converting to qmlmap to qmlseamap

ADDED also note need to clean up exit from QT readport function as close&clean .
as some times getting a read error

OK sorted , possible can get rid of the counter since have break in the bits
Archive Updated
Updated again (wrong file)
have fun +
BR
Alex

Attachments:

dynamic2.tar.gz (3.79 KB)

[alexfish]

Hi All
Updated archive above

BR
Alex