Comments on: Create a scrollable Map with Cells – Part I

By: Simi

Simi — Sat, 04 Feb 2012 17:50:52 +0000

Hi I’m trying to create a simple path finding app in android. I want to know how to implement A* algorithm in Android.

By: Snowie

Snowie — Fri, 19 Aug 2011 03:24:43 +0000

Hi Martin, I would like to implement the whole background and I’ve seen the onDraw method of this tutorial: http://www.droidnova.com/playing-with-graphics-in-android-part-vii,220.html but I’m having problems, this is my current onDraw() method:

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public void onDraw(Canvas canvas) {
	    canvas.drawBitmap(_bitmapCache.get(R.drawable.abstrakt), 0, 0, null);
	}

but I’m getting this error when I implement this code into your ScrollActivity project:

08-19 03:15:21.893: ERROR/AndroidRuntime(550): FATAL EXCEPTION: Thread-8
08-19 03:15:21.893: ERROR/AndroidRuntime(550): java.lang.NullPointerException
08-19 03:15:21.893: ERROR/AndroidRuntime(550): at android.graphics.Canvas.throwIfRecycled(Canvas.java:954)
08-19 03:15:21.893: ERROR/AndroidRuntime(550): at android.graphics.Canvas.drawBitmap(Canvas.java:980)
08-19 03:15:21.893: ERROR/AndroidRuntime(550): at com.bix.scrollmap.CellMapSurfaceView.onDraw(CellMapSurfaceView.java:479)
08-19 03:15:21.893: ERROR/AndroidRuntime(550): at com.bix.scrollmap.CellMapSurfaceView$MapThread.run(CellMapSurfaceView.java:120)

Am I miss anything or do I have to change anything else? Thanks for the tutorial btw!

By: Martin

Martin — Wed, 26 May 2010 19:53:32 +0000

Thank you. Currently I use a play ArrayList where I just know the position on the map by dividing and modulo operation

By: Vasil Nonchev

Vasil Nonchev — Wed, 26 May 2010 11:02:59 +0000

Great tutorial, Martin.

My recommendation, however is if you don’t want to use a two dimensional array for the map, as it may be dynamically changing, to use ArrayList

By: makboney

makboney — Thu, 08 Apr 2010 04:56:05 +0000

hey Martin…

thats a nice one…helped me a lot…

but could u please give some idea on custom map not google map…

thanks

By: Ivan

Ivan — Wed, 10 Mar 2010 17:44:58 +0000

Amazing tutorial. I was looking for a good example using SurfaceView.

By: Martin

Martin — Sat, 06 Feb 2010 11:12:30 +0000

Whole background: Take a look at the onDraw method of this tutorial: http://www.droidnova.com/playing-with-graphics-in-android-part-vii,220.html

To make it smoother is one topic on the next two parts.
I’m in the final week in my current semester. Please give me the time

By: Jonas

Jonas — Fri, 05 Feb 2010 23:26:35 +0000

Hi Martin!

Very nice tutorial, this helped me a lot! Keep the good work up!

Can’t wait to next one but i need some help.. pretty new to this! How do you implement a whole background? Or do you need to it for every cell?
And any tips before the next tutorial, how to do it smoother?

Thanks!

By: Michael

Michael — Tue, 26 Jan 2010 07:44:59 +0000

Hi Martin,

very nice and useful tutorial. Although rendering the complete scene, this is very useful. Can’t wait for the next tutorial part, showing of how to do with 200×200 cells

Just mail me, if you’re going to do so!

By: Martin

Martin — Sun, 17 Jan 2010 19:23:12 +0000

Hey,

your right, my conventions are from the j2ee projects where I learned Java. We had Checkstyle installed to check that every variable has its prefix _
Currently I “learn” to use the m prefix, which is defined by the Android Style Guide.