iOS Code Snippet imageloader with file cache

It's better to using this:https://www.b4x.com/android/forum/threads/imageloaderv2.75022/


dependson:HttpUtils2,KeyValueStore2,iSQL,iRandomAccessFile,iEncryption

iCache:

'Class module depends on KeyValueStore
Sub Class_Globals
    Private kvscache As KeyValueStore
End Sub

'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize
    Initialize2("","")
End Sub
'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize2(dir As String,filename As String)
    If dir=Null Or dir.Length=0 Or filename=Null Or filename.Length=0 Then
        kvscache.Initialize(File.DirTemp,"test.tmp")
    Else
        kvscache.Initialize(dir,filename)
    End If
 
End Sub
'will encode the key to md5
Public Sub ContainsKey(key As String) As Boolean
    key=comm.getMD5(key)
    Return kvscache.ContainsKey(key)
End Sub

Public Sub getString(key As String,def As String) As String
    key=comm.getMD5(key)
    Return kvscache.GetDefault(key,def)
End Sub
Public Sub putString(key As String,val As String)
    key=comm.getMD5(key)
    kvscache.Put(key,val)
End Sub
Public Sub getDef(key As String,def As Object) As Object
    If kvscache.ContainsKey(key) Then Return getObjectFromCache(key) Else Return def
End Sub
Public Sub putObj(key As String,val As Object)
    key=comm.getMD5(key)
    kvscache.Put(key,val)
End Sub
Public Sub getObjEnc(key As String,pass As String) As Object
    Return getObjEncDef(key,pass,Null)
End Sub
Public Sub getObjEncDef(key As String,pass As String,def As Object) As Object
    key=comm.getMD5(key)
    If kvscache.ContainsKey(key) Then Return kvscache.GetEncrypted(key,pass) Else Return def
End Sub
Public Sub putObjEnc(key As String,val As Object,pass As String)
    key=comm.getMD5(key)
    kvscache.PutEncrypted(key,val,pass)
End Sub
Public Sub close
    kvscache.Close
End Sub
Public Sub getBitmap(key As String) As Bitmap
    key=comm.getMD5(key)
'    Dim bmp As Bitmap
'    bmp.Initialize(File.DirTemp,key)
'    Return bmp
    Return kvscache.GetBitmap(key)
End Sub
Public Sub putBitmap(key As String,bmp As Bitmap)
    key=comm.getMD5(key)
'    kvscache.PutSimple(key,File.Combine(File.DirTemp,key))
'    Dim ops As OutputStream= File.OpenOutput(File.DirTemp,key,False)
'    bmp.WriteToStream(ops,100,"PNG")
'    ops.Close
    kvscache.PutBitmap(key,bmp)
End Sub
Public Sub getObjectFromCache(key As String) As Object
    key=comm.getMD5(key)
    Return kvscache.Get(key)
End Sub
Public Sub remove(key As String)
    key=comm.getMD5(key)
    kvscache.Remove(key)
End Sub
Public Sub clearAllCache
    kvscache.DeleteAll
End Sub

imagedownloader

'depends on iCache,HttpUtils2
Sub Class_Globals
'    Public gravitymode As Object=Null
    Private taskobjs,taskkeys As List
End Sub

'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize
    taskkeys.Initialize
    taskobjs.Initialize
  
End Sub
Public Sub addJob2(url As String,iv As ImageView,usingcache As Boolean)
    Dim m As Map
    m.Initialize
    m.Put("url",url)
    m.Put("iv",iv)
    Dim key As String=comm.getMD5(url)
    m.Put("key",key)
    m.Put("cache",usingcache)
    If usingcache And comm.cache.ContainsKey(key) Then
        iv.Bitmap=comm.cache.getBitmap(key)
'        If gravitymode<>Null Then iv.ContentMode=gravitymode
    Else
        If taskkeys.IndexOf(key)>-1 Then
            Log("on going:"&url)
        Else
            taskobjs.Add(m)
            taskkeys.Add(key)
            Dim j As HttpJob
            j.Initialize(key, Me)
            j.Download(url)  
        End If
    End If
End Sub
Public Sub addJob(url As String,iv As ImageView)
    addJob2(url,iv,True)
End Sub
Sub JobDone(Job As HttpJob)
    If Job.Success Then
        Dim bmp As Bitmap = Job.GetBitmap
        Dim idx As Int=taskkeys.IndexOf(Job.JobName)
        Dim m As Map=taskobjs.Get(idx)
        If m.GetDefault("cache",False) Then comm.cache.putBitmap(Job.JobName,bmp)
        Dim iv As ImageView=m.Get("iv")
        taskkeys.RemoveAt(idx)
        taskobjs.RemoveAt(idx)
        iv.Bitmap=bmp
'        If gravitymode<>Null Then iv.ContentMode=gravitymode
    Else
        Log("Error downloading image: " & Job.JobName & CRLF & Job.ErrorMessage)
    End If
    Job.Release
End Sub

comm

'Code module

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'Public variables can be accessed from all modules.
    Public bc As ByteConverter
    Public cache,data As iCache
    Public imgldr As ImageDownloader
End Sub
Public Sub Initialize
    data.Initialize2(File.DirDocuments,"mdata.dat")
    cache.Initialize
    Starter.start
    imgldr.Initialize
End Sub
Public Sub isLogin As Boolean
    Return data.getDef("islogin",False)
End Sub
Public Sub setLogin(b As Boolean)
    data.putObj("islogin",b)
End Sub
Sub loadimg (imgurl As String,v As ImageView)
    imgldr.addJob(imgurl,v)
End Sub
Sub loadimg_nocache (imgurl As String,v As ImageView)
    imgldr.addJob2(imgurl,v,False)
End Sub
Public Sub resize(width As Int,height As Int,pg As Page)
    '////// Start resize all views to fit all screensize //////
    Dim ratiox As Float = width/320 'iphone 4 3.5" = x320
    Dim ratioy As Float = height/560 'iphone 4 3.5" = y480 - 20 !

    For Each v As View In pg.RootPanel.GetAllViewsRecursive
        If v.Tag="drs" Then'drs= dont chg my size
            v.Left = v.Left*ratiox
            v.Top = v.Top*ratioy
        Else if v.Tag="drm" Then'drm = dont resize me...
         
        Else
            v.Width = v.Width*ratiox
            If v.Height<>1 Then v.Height = v.Height*ratioy
            v.Left = v.Left*ratiox
            v.Top = v.Top*ratioy
'            Log(v.Width&"*"&v.Height)
        End If
    Next
'////// End resize all views ///////
End Sub
Public Sub str2hex(str As String) As String
    Return bc.HexFromBytes(str.GetBytes("utf8"))
End Sub
public Sub getMD5(str As String) As String
    Dim buf() As Byte=str.GetBytes("utf8")
    Dim mD As MessageDigest
    Dim retbuf() As Byte=mD.GetMessageDigest(buf,"MD5")
    Dim retstr As String=bc.HexFromBytes(retbuf)
'    Log(retstr)
    Return retstr
End Sub

 

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