B4J Question Apache PDFBox

[amaxco]

Hi,

I am inquiring about whether there is any implementation of the above library in B4J and if it has a built-in viewer.

Regards

 

[Daestrum]

I played with this a while back, didn't seem too hard to use with javaobjects.
You can render the generated page to an ImageView.
This is the code I used to get a true A4 sized image on my screen. It returns an (fx) Image that I just put into an ImageView.

Sub renderPage(p As Int) As Image ' p is page number
 Dim scrn As JavaObject
 Dim dpi As Float = scrn.InitializeStatic("javafx.stage.Screen").RunMethodJO("getPrimary",Null).RunMethod("getDpi",Null)
 Return utils.RunMethodjo("toFXImage",Array(renderer.RunMethod("renderImageWithDPI",Array(p,dpi)),Null))
End Sub

 

[amaxco]

I played with this a while back, didn't seem too hard to use with javaobjects.
You can render the generated page to an ImageView.
This is the code I used to get a true A4 sized image on my screen. It returns an (fx) Image that I just put into an ImageView.

Sub renderPage(p As Int) As Image ' p is page number
Dim scrn As JavaObject
Dim dpi As Float = scrn.InitializeStatic("javafx.stage.Screen").RunMethodJO("getPrimary",Null).RunMethod("getDpi",Null)
Return utils.RunMethodjo("toFXImage",Array(renderer.RunMethod("renderImageWithDPI",Array(p,dpi)),Null))
End Sub

Thank you for your reply.

I really want to display the whole document in a viewer similar to Acrobat Reader. I thought the webview could handle that in a similar manner as the WebBrowser object that we used in VB6, in connection of Acrobat Reader.

Regards,

 

[DonManfred]

The android webview does not have a PDF viewer integrated.
Edit: Sorry, B4J forum... I dont think B4 webview does not have a PDF-Viewer integrated too.

 

[Erel]

This is the code I used to get a true A4 sized image on my screen. It returns an (fx) Image that I just put into an ImageView.

What is renderer in this code? Where is the code that loads the PDF file?

 

[Daestrum]

I did find an alternative - it uses a webview and a free js library. (ViewerJS)
Seems simple to get it display pdf's (it also can display other file types too)

The code is

Sub AppStart ....
...
Dim wv As WebView
Dim engine As JavaObject
wv.Initialize("")
wv.PrefWidth = 600
wv.PrefHeight = 600
MainForm.RootPane.AddNode(wv,0,10,-1,-1)
engine = asJO(wv).RunMethodJO("getEngine",Null)

' where you unpacked the viewer to
Dim viewer As String = "C:/temp/ViewerJS/index.html"

' the file you want to display
Dim testfile As String = "C:/temp/pdftest.pdf"

Dim s As String = File.GetUri("",viewer) & "#" & File.GetUri("",testfile)
engine.RunMethod("load",Array(s))
Log(s)
End Sub
Sub asJO(o As JavaObject)As JavaObject
Return o
End Sub

 

[Daestrum]

@Erel - sorry that was just a snippet of the code I used , I can post the full code if you want.
Some of the missing bits (all javaobjects)

thisDoc.InitializeNewInstance("org.apache.pdfbox.pdmodel.PDDocument",Null)
renderer.InitializeNewInstance("org.apache.pdfbox.rendering.PDFRenderer",Array(thisDoc))
utils.InitializeStatic("javafx.embed.swing.SwingFXUtils")

 

[amaxco]

@Erel - sorry that was just a snippet of the code I used , I can post the full code if you want.
Some of the missing bits (all javaobjects)

thisDoc.InitializeNewInstance("org.apache.pdfbox.pdmodel.PDDocument",Null)
renderer.InitializeNewInstance("org.apache.pdfbox.rendering.PDFRenderer",Array(thisDoc))
utils.InitializeStatic("javafx.embed.swing.SwingFXUtils")

I appreciate if you could post the full code and an example app, unless it it requires a reply from @Erel

 

[Erel]

unless it it requires a reply from @Erel

I'm sure that it will be helpful for many members...

 

[Daestrum]

here is the code - I was just trying out creating pdf and printing.(never got round to adding bells and whistles like page size, margins etc)

There are very few comments in the code as I was writing it directly from the api docs.

 

[amaxco]

here is the code - I was just trying out creating pdf and printing.(never got round to adding bells and whistles like page size, margins etc)

There are very few comments in the code as I was writing it directly from the api docs.

Thrown error

Waiting for debugger to connect...
Program started.
ط£ط؛ط³ 23, 2017 9:43:16 ظ… org.apache.pdfbox.pdmodel.font.FileSystemFontProvider loadDiskCache
WARNING: New fonts found, font cache will be re-built
ط£ط؛ط³ 23, 2017 9:43:16 ظ… org.apache.pdfbox.pdmodel.font.FileSystemFontProvider <init>
WARNING: Building on-disk font cache, this may take a while
ط£ط؛ط³ 23, 2017 9:43:29 ظ… org.apache.pdfbox.pdmodel.font.FileSystemFontProvider <init>
WARNING: Finished building on-disk font cache, found 662 fonts
Error occurred on line: 55 (pdfLib)
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:131)
at b4j.example.pdflib._savedocument(pdflib.java:222)
at b4j.example.main._appstart(main.java:102)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:613)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:231)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:90)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:93)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:77)
at b4j.example.main.start(main.java:38)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$163(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$149(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.FileNotFoundException: c:\temp\pdftest.pdf (The system cannot find the path specified)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:162)
at org.apache.pdfbox.pdmodel.PDDocument.save(PDDocument.java:1118)
at org.apache.pdfbox.pdmodel.PDDocument.save(PDDocument.java:1106)
... 31 more

 

[Daestrum]

Looks like you don't have a c:/temp directory in which to save the pdf file.

Caused by: java.io.FileNotFoundException: c:\temp\pdftest.pdf (The system cannot find the path specified)

 

[amaxco]

Looks like you don't have a c:/temp directory in which to save the pdf file.

Hi Daestrum,

You are correct! Creating the folder has fixed the problem.

In my first post I mentioned a viewer which is my prime concern. Of course your wrapper of rendering will be useful to other members, in addition to what @warwound had done https://www.b4x.com/android/forum/threads/jpdfjet.37842/

What I truly need is the viewer you explained about, showing a screenshot, in your post #6

Regards

 

[Daestrum]

The code I posted in post #6, is the entire code needed to show the viewer and load a file into it.
a, create a webview.
b, get the engine object of the webview.
c, create the uri to the VeiwerJS index.html and add '#' and the uri of the file you want to display
d, load the uri into the webengine

Display file =)

 

[amaxco]

I executed the code without error but nothing appears. Below is my modified code.
1. In the Process_Globals - I have Private webview2 As WebView
2. the AppStart - I have webview2.Initialize("")
3. I have a button to trigger ShowPdfFile

Sub ShowPdfFile()
'ShowPdfFile("C:/temp/pdftest.pdf")
engine = asJO(webview2).RunMethodJO("getEngine",Null)
webview2.PrefWidth=Pane2.width-25
webview2.PrefHeight=Pane2.height-25
Dim viewer As String = "C:/temp/ViewerJS/index.html"
Dim testfile As String = "C:/temp/pdftest.pdf"
Dim s As String = File.GetUri("",viewer) & "#" & File.GetUri("",testfile)
engine.RunMethod("load",Array(s))
Log(s)
End Sub

This is Log(s) output:
file:/C:/temp/ViewerJS/index.html#file:/C:/temp/pdftest.pdf

What could I have done wrong

 

[Daestrum]

Have you checked that the ViewerJS.zip (from http://viewerjs.org/) unpacked correctly into c:/temp/ViewerJS directory.

 

[amaxco]

Have you checked that the ViewerJS.zip (from http://viewerjs.org/) unpacked correctly into c:/temp/ViewerJS directory.

Yes, I downloaded from the above website and unpacked into the recommended folder. As I mentioned there is no error in execution but the webview remains blank.

 

[amaxco]

I am able to show ViewrJS in the webview!

Alas! The pdf file is not showing. I will continue trying and later feed you back

 

[amaxco]

Please note that the viewer show the file name in the title bar. Still the file content does not display.

 

[alwaysbusy]

I'm using the same library (modified for ABMaterial) and my url looks like this:

./viewerpdf.html?file=../PDF/1.pdf

so myabe in your case you could try something similar?

file:/C:/temp/ViewerJS/index.html?file=file:/C:/temp/pdftest.pdf