Attempt to invoke virtual method crash in AndroidPdfViewer - pdf

Using the AndroidPdfViewer package.
My build.gradle code:
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
implementation("com.github.bumptech.glide:glide:4.5.0") {
exclude group: "com.android.support"
}
implementation "com.android.support:support-fragment:26.1.0"
compile 'com.github.barteksc:android-pdf-viewer:2.8.2'
}
Activity XML file:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.github.barteksc.pdfviewer.PDFView
android:id="#+id/pdfView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
Activity code:
package eu.myapp.myapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.github.barteksc.pdfviewer.PDFView;
public class activity_fact_sheet extends AppCompatActivity {
PDFView pdfView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
PDFView pdfView = (PDFView) findViewById(R.id.pdfView);
pdfView.fromAsset("file2.pdf").load();
}
}
file2.pdf located in app > src > main > assets
Error on run:
01-18 11:59:25.475 29674-29674/eu.myapp.myapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: eu.myapp.myapp, PID: 29674
java.lang.RuntimeException: Unable to start activity ComponentInfo{eu.myapp.myapp/eu.myapp.myapp.activity_fact_sheet}: java.lang.NullPointerException: Attempt to invoke virtual method 'com.github.barteksc.pdfviewer.PDFView$Configurator com.github.barteksc.pdfviewer.PDFView.fromAsset(java.lang.String)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2924)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2985)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1635)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6692)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'com.github.barteksc.pdfviewer.PDFView$Configurator com.github.barteksc.pdfviewer.PDFView.fromAsset(java.lang.String)' on a null object reference
at eu.myapp.myapp.activity_fact_sheet.onCreate(activity_fact_sheet.java:17)
at android.app.Activity.performCreate(Activity.java:6912)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1126)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2877)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2985) 
at android.app.ActivityThread.-wrap14(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1635) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6692) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358) 
Steps taken to resolve it:
added PDFView pdfView; to activity code above #Override and under public class activity_fact_sheet extends AppCompatActivity {
Also checked to see if it was an issue with my activity opening method (it wasn't).
It seems the error is thrown on pdfView.fromAsset("file2.pdf").load(); in the activity code. That makes it seem to me that it cannot find file2.pdf in the assets, but I'm probably wrong.
The app crashes when you try to open the activity.
Tried to implement it using this video.

OK, I found another topic on stackexchange (besides the countless ones on nullpointer exceptions - which didn't help me). This has the code that works. Just import
compile 'com.github.barteksc:android-pdf-viewer:2.8.2'
compile 'org.apache.commons:commons-collections4:4.1'
in your gradle build file.
Then make sure you have the <uses-permission android:name="android.permission.WRITE_SETTINGS"/> permission in AndroidManifest.xml. (You should already have had this anyway.)
Then make sure to copy his code in your activity where you want to show the PDF. Change public static final string SAMPLE_FILE to the actual pdf you want to show (in your assets folder).
If you get an error on the TAG in Log.e(TAG, String.format("%s %s, p %d", sep, b.getTitle(), b.getPageIdx())); you must add private static final String TAG = "youractivitynamehere"; just under the public static final String SAMPLE_FILE = "yourfilehere.pdf";
That's all! Hope anyone else searching for this issue will find this.

Add this code in your XML file
<com.github.barteksc.pdfviewer.PDFView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/pdfView"
></com.github.barteksc.pdfviewer.PDFView>

Related

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I am taking the coursera course for mobile application development and I am doing my first project, my build launches successfully then immediately crashes. I am not sure why it is doing this so any insight into the matter would be greatly appreciated. Below is my build...
package com.example.video_player
import android.R
import android.net.Uri
import android.net.Uri.*
import android.os.Bundle
import android.widget.MediaController
import android.widget.VideoView
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override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
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mediaController.setAnchorView(videoView)
val uri:Uri = parse(
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<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.video_player.MainActivity">
<VideoView
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android:layout_height="308dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
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This is my first build and i am following a tutorial and am just getting error after error, when i get the errors to clear the app crashes directly after launch.

emre1512 Noty RelativeLayout creation in Kotlin

I have a simple MainActivity with a simple main layout like this:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
... />
</androidx.constraintlayout.widget.ConstraintLayout>
I need to activate Noty on this activity. What I need to know is how to create RelativeLayout "yourLayout" in its simple exmple in Kotlin.
Noty.init(YourActivity.this, "Your warning message", yourLayout, Noty.WarningStyle.SIMPLE).show();
Thank you!
Add an android:id attribute to your ConstraintLayout tag:
android:id="#+id/root"
Now you can fetch a reference to that ConstraintLayout in code:
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Recyclerview not displaying list item but gray background and text "android...RecyclerView"

i am a new to Kotlin Android development,i added recycler view to my project and then move the icon to the layout according to the tutorial i was watching but it not displaying anything except gray background and this black text "andriod...recycler" instead of displaying the list items samples as in the tutorial
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it on Api28, here is the activity_hobbies.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
this is HobbiesActivity.tk
package org.blessedmedia.www.kotlinapp
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
class HobbiesActivity : AppCompatActivity(){
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_hobbies)
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if you need any more file to provide solution.kindly comment

App crash caused by data binding related to java.lang.Runnable android.databinding.ViewDataBinding.mRebindRunnable

The exception is the following:
java.lang.NullPointerException: Attempt to read from field 'java.lang.Runnable android.databinding.ViewDataBinding.mRebindRunnable' on a null object reference
at android.databinding.ViewDataBinding.access$100(ViewDataBinding.java:51)
at android.databinding.ViewDataBinding$5.onViewAttachedToWindow(ViewDataBinding.java:142)
at android.view.View.dispatchAttachedToWindow(View.java:14525)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2836)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2843)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1364)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:606)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Let me try my best to make the description brief and clear.
First, this is related to a layout added dynamically. The activity's data binding works perfectly without any problem.
Here is the layout foo_view:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="foo"
type="net.mydomain.myapp.MyActivity.Foo" />
<import type="android.view.View" />
</data>
<!--For the sake of debugging, no data binding is actually used-->
...
</layout>
In MyActivity.java:
public class MyActivity extends AppCompatActivity {
public class Foo{
...
}
...
addFoo(){
FooViewBinding binding = DataBindingUtil.inflate(LayoutInflater.from(this), R.layout.foo_view, myGridLayout, true);
Foo foo = new Foo();
binding.setFoo(foo);
}
}
The app cashes immediately upon the start of MyActivity. The crash is not caused by a specific line of code.
Could anyone shed some light on this?
[Edit] 2016-06-30
The crash happens on a Lollipop, but same code works fine on a Jelly Bean
Just in case someone has the same problem, this errors occurs when you change the tag (i.e. view.setTag(object)) of a data-binding enabled view, as the data binding library uses the tag for itself.
in my case,
If I use <androidx.constraintlayout.widget.Group/> in 'merge'it gives an error on some screens.
<merge tools:parentTag="androidx.constraintlayout.widget.ConstraintLayout">
<androidx.constraintlayout.widget.Group
android:id="#+id/constraint_group_active"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="#{data != null}"
app:constraint_referenced_ids="txt_offering_slogan,view_extra_gift,iv_offering,txt_offering_title,txt_offering_subtitle,txt_buy_extra_gift"
tools:visibility="visible" />
</merge>

Gradle flavors, applicationId and not resolved custom view attributes

I have a custom view based on GridLayout:
package com.mycompany.myapp;
...
public class GridLayoutForceSizeCells extends GridLayout
{
}
I have defined an xml with custom attributes for this class:
<?xml version="1.0" encoding="utf-8" ?>
<resources>
<declare-styleable name="GridLayoutForceSizeCells">
<attr name="totalImages" format="integer" />
<attr name="desiredColumnCount" format="integer" />
<attr name="spacing" format="dimension" />
<attr name="autoGenerate" format="boolean" />
</declare-styleable>
</resources>
Then, I have a layout using this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:wheel="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.mycompany.myapp.GridLayoutForceSizeCells
xmlns:grid="http://schemas.android.com/apk/res/com.mycompany.myapp"
android:padding="3dp"
android:id="#+id/cellsGrid"
android:layout_width="match_parent"
android:layout_height="match_parent"
grid:desiredColumnCount="20"
grid:totalImages="0"
grid:spacing="1dp"
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</LinearLayout>
The problem I am encountering is that when I change applicationId through a gradle flavor custom attributes are not resolved. I have read in gradlew help that the application package is the one used for R when it is decoupled using gradlew applicationId entry. So, applicationId should not affect my custom attributes package. But when I set applicationId to anything different from com.mycompany.myapp an error arises claiming that attributes can't be resolved.
Has anybody found a solution to this?
Cheers.
Finally fix it using xmlns:grid="http://schemas.android.com/apk/res-auto" to let it resolve the package for me in the layout file instead of the full package name.