Difference between revisions of "Android-app-using-Kotlin/C3/Display-Search-Result/English"

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(Created page with " {| style="border-spacing:0;" | style="background-color:#c0c0c0;border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| <cent...")
 
 
Line 68: Line 68:
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In the '''Palette''' search box, type '''RecyclerView.'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In the '''Palette''' search box, type '''RecyclerView.'''
  
Then drag the '''RecyclerView''' to the layout.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Drag '''RecyclerView''' to the layout
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Then drag the '''RecyclerView''' to the layout.
  
'''Add project Dependency''' pop up box appears.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Pop-up box
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Add project Dependency''' pop up box appears.
  
Click on '''Ok''' button to accept the dependency.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|Click on '''Ok''' button
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Click on '''Ok''' button to accept the dependency.
  
 
Wait until the '''Gradle build''' is finished.
 
Wait until the '''Gradle build''' is finished.
Line 80: Line 86:
  
 
'''RecyclerView'''
 
'''RecyclerView'''
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| * '''RecyclerView '''recycles''' '''the visible views on the screen to show new views.
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|  
 +
* '''RecyclerView '''recycles''' '''the visible views on the screen to show new views.
 
* When we scroll, it will use the same place to display new images.
 
* When we scroll, it will use the same place to display new images.
* This way '''RecyclerView''' is '''efficient '''and '''faster.'''
+
* This way '''RecyclerView''' is efficient and faster.
 
|-
 
|-
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Switch back to '''Android Studio'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Switch back to '''Android Studio'''
Line 90: Line 97:
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type unique ID as '''videos_recyclerview'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type unique ID as '''videos_recyclerview'''
  
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In the '''Attributes''' window, in unique '''ID '''type '''videos_recyclerview.'''
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In the '''Attributes''' window, type '''videos_recyclerview''' in the '''ID''' field.
  
Join the top '''constraint''' of '''RecyclerView '''to the bottom''' '''of the '''Selectedoption''' '''TextView.'''
+
Join the top '''constraint''' of '''RecyclerView '''to the bottom of the '''Selectedoption TextView.'''
  
 
Align the other '''constraints''' of '''RecyclerView''' as shown here.
 
Align the other '''constraints''' of '''RecyclerView''' as shown here.
Line 98: Line 105:
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| demo
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| demo
  
Change its '''layout_width''' and '''layout_height''' attribute to match_constraint  
+
Change its '''layout_width''' &'''layout_height attribute''' to '''match_constraint'''.
  
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Change its '''layout_width''' and '''layout_height attribute''' to '''match_constraint '''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Change its '''layout_width''' and '''layout_height attribute''' to '''match_constraint '''
Line 115: Line 122:
 
Right-click on '''App''' then select '''New '''<nowiki>=> </nowiki>'''XML '''<nowiki>=> </nowiki>'''Layout XML File'''
 
Right-click on '''App''' then select '''New '''<nowiki>=> </nowiki>'''XML '''<nowiki>=> </nowiki>'''Layout XML File'''
  
'''Configure Component '''window appears.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Configure Component '''window >> type '''my_customlayout '''>> click on '''Finish '''button.
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|'''Configure Component '''window appears.
  
In the '''Layout File Name,''' type '''my_customlayout '''and click on '''Finish '''button'''.'''
+
In the '''Layout File Name,''' type '''my_customlayout '''and click on '''Finish '''button.
  
 
|-
 
|-
Line 154: Line 163:
  
 
|-
 
|-
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Open '''drawable''' >> '''project''' and select '''ic_launcher'''
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Open '''Drawable''' >> '''Project''' and select '''ic_launcher'''
  
 
Give a unique ID : '''video_thumbnail'''
 
Give a unique ID : '''video_thumbnail'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| A '''Resources''' dialog box opens.
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| A '''Resources''' dialog box opens.
  
On the left side, under '''drawable''', click '''project,''' then select the image '''ic_launcher '''and click on '''OK''' button.
+
On the left side, under '''Drawable''', click '''Project,''' then select the image '''ic_launcher '''and click on '''OK''' button.
  
 
In the '''Attribute''' window, type '''video_thumbnail'''
 
In the '''Attribute''' window, type '''video_thumbnail'''
Line 252: Line 261:
 
|-
 
|-
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point to''' MyAdapter.kt'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point to''' MyAdapter.kt'''
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| A new file gets created under the hierarchy, named '''MyAdapter.kt'''
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| A new file gets created named '''MyAdapter.kt'''
  
 
In this, we will write the '''Kotlin''' code for the '''Adapter'''.
 
In this, we will write the '''Kotlin''' code for the '''Adapter'''.
Line 288: Line 297:
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Copy- paste the code
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Copy- paste the code
  
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Now we '''implement''' the required '''methods'''.
+
Point to the code line as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Now we will '''implement''' the required '''methods'''.
  
 
First we will create the '''onCreateViewHolder method.'''
 
First we will create the '''onCreateViewHolder method.'''
  
Type this code for the '''method'''.  
+
Copy and paste the code for this '''method''' from the '''Code file myadapter.kt'''
  
 
Here we created a '''view''' having '''my_customlayout.xml''' and '''returned''' it through '''MyViewHolder class.'''
 
Here we created a '''view''' having '''my_customlayout.xml''' and '''returned''' it through '''MyViewHolder class.'''
Line 302: Line 313:
 
Type the following code below '''onCreateViewHolder method.'''
 
Type the following code below '''onCreateViewHolder method.'''
  
Press Alt+Enter keys and resolve the warnings.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Press '''Alt+Enter''' keys
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|Press '''Alt+Enter''' keys and resolve the warnings.
 +
 
 +
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
  
We will use the '''position variable''' to know which item we are filling.
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|We will use the '''position variable''' to know which item we are filling.
  
 
We first get the '''VideoItem object '''which is being filled currently in '''singleVideoItem'''.
 
We first get the '''VideoItem object '''which is being filled currently in '''singleVideoItem'''.
  
 
|-
 
|-
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|  
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Here we set the text of the '''video_title '''and''' video_level''' from the '''singleVideoItem’s '''values.
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Here we set the text of the '''video_title '''and''' video_level''' from the '''singleVideoItem’s '''values.
  
Line 318: Line 335:
 
We can get the thumbnail from a specific '''spoken tutorial YouTube URL.'''
 
We can get the thumbnail from a specific '''spoken tutorial YouTube URL.'''
  
The '''URL''' has this format:  
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|The '''URL''' has this format:  
 
[https://i.ytimg.com/vi/videoId/sddefault.jpg https://i.ytimg.com/vi/videoId/sddefault.jpg]
 
[https://i.ytimg.com/vi/videoId/sddefault.jpg https://i.ytimg.com/vi/videoId/sddefault.jpg]
  
 
So we will use the '''URL''' and pass the '''videoID''' for which we need the thumbnail image.
 
So we will use the '''URL''' and pass the '''videoID''' for which we need the thumbnail image.
  
We have used '''Picasso''', to load the image into '''video_thumbnail ImageView.'''
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|We have used '''Picasso''', to load the image into '''video_thumbnail ImageView.'''
  
 
|-
 
|-
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|  
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| We have created '''setOnClickListener method''' for''' linear layout''' and named it as '''itemLinearLayout'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| We have created '''setOnClickListener method''' for''' linear layout''' and named it as '''itemLinearLayout'''
  
 
When the thumbnail is clicked, it will play the '''YouTube''' video in the '''ThirdActivity'''.
 
When the thumbnail is clicked, it will play the '''YouTube''' video in the '''ThirdActivity'''.
  
We have not created the '''ThirdActivity '''and so it shows an error now.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|We have not created the '''ThirdActivity '''and so it shows an error now.
  
 
We pass the '''videoID''' and '''videoTitle''' to the '''ThirdActivity''' by '''putExtra method.'''
 
We pass the '''videoID''' and '''videoTitle''' to the '''ThirdActivity''' by '''putExtra method.'''
  
We have added a required flag of '''Intent.FLAG_ACTIVITY_NEW_TASK.'''
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|We have added a required flag of '''Intent.FLAG_ACTIVITY_NEW_TASK.'''
  
 
This is required by '''YouTube''' activity.
 
This is required by '''YouTube''' activity.
  
Then we start the '''intent''' using '''mContext variable.'''
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|Then we start the '''intent''' using '''mContext variable.'''
  
 
|-
 
|-
Line 346: Line 378:
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type the next '''method getItemCount '''below '''onBindViewHolder method.'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type the next '''method getItemCount '''below '''onBindViewHolder method.'''
  
The '''function getItemCount '''returns the number of items to be shown inside '''RecyclerView.'''
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|The '''function getItemCount '''returns the number of items to be shown inside '''RecyclerView.'''
  
 
The '''adapter''' code is completed now.
 
The '''adapter''' code is completed now.
Line 355: Line 390:
  
 
|-
 
|-
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|  
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Project >> Right-click on app >> New >> Activity >> Empty activity
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| On the top left panel, under '''project''', go to '''app.'''
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| On the top left panel, under '''project''', go to '''app.'''
  
Right-click on '''app''' then select '''New '''-> '''Activty '''-> '''Empty Activity'''
+
Right-click on '''app''' then select '''New '''-> '''Activity '''-> '''Empty Activity'''
  
 
|-
 
|-
Line 416: Line 451:
  
 
|-
 
|-
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|  
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In '''onCreate method''' type this code.
 
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In '''onCreate method''' type this code.
  
Line 435: Line 470:
 
We can see that the '''video''' thumbnail loads on the next page.
 
We can see that the '''video''' thumbnail loads on the next page.
  
Scroll down to see all the thumbnails that are loaded for the selected '''FOSS''' and language.
+
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Scroll down
 +
 
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|Scroll down to see all the thumbnails that are loaded for the selected '''FOSS''' and language.
 +
 
 +
|-
 +
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point as per narration
  
Video title and level are displayed as well.
+
| style="border:1pt solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|Video title and level are displayed as well.
  
 
When we select a video the '''third activity''' opens.
 
When we select a video the '''third activity''' opens.

Latest revision as of 11:42, 15 July 2019

Visual Cue
Narration
Slide 1: Welcome to the Spoken Tutorial on Display Search Result.
Slide 2:

Learning Objectives

In this tutorial we will learn to
  • Use RecyclerView to display the thumbnail of videos
  • Get the thumbnail from a specific Spoken Tutorial YouTube URL
  • Pass the videoID of the selected Spoken Tutorial
  • Run the Kotlin App and
  • Display the thumbnail of the selected video
Slide 3:

System requirement

To record this tutorial, I am using
  • Ubuntu Linux 16.04 operating system
  • Android Studio version 3.x and
  • Android Phone with minimum of Android OS version 4.03
Slide 4:

Pre-requisites

To follow this tutorial, you should have basic knowledge
  • Java programming language and
  • Android Studio

If not, then go through the relevant tutorials on this website.

Slide 5:

Recap

* Earlier, we parsed the JSON data received from the server
  • The data is stored in an arraylist finalResultsArrayList
  • We will use this arraylist to display the searched result to the user
Open the Android studio from the launcher bar. Let us open Android Studio.
Click on ST search Open the project ST Search.
Click on activity_second.xml Go to activity_second.xml
We will use the tool RecyclerView to display the thumbnail of videos.
In palette search box, type RecyclerView. In the Palette search box, type RecyclerView.
Drag RecyclerView to the layout Then drag the RecyclerView to the layout.
Pop-up box Add project Dependency pop up box appears.
Click on Ok button Click on Ok button to accept the dependency.

Wait until the Gradle build is finished.

Slide 6:

RecyclerView

  • RecyclerView recycles the visible views on the screen to show new views.
  • When we scroll, it will use the same place to display new images.
  • This way RecyclerView is efficient and faster.
Switch back to Android Studio Let us switch back to Android Studio interface.
Type unique ID as videos_recyclerview In the Attributes window, type videos_recyclerview in the ID field.

Join the top constraint of RecyclerView to the bottom of the Selectedoption TextView.

Align the other constraints of RecyclerView as shown here.

demo

Change its layout_width &layout_height attribute to match_constraint.

Change its layout_width and layout_height attribute to match_constraint

It helps to adjust the space occupied by the RecyclerView.

Next we will create our own custom layout file which will be used to fill a single item of RecyclerView.
click on app then select New => XML => Layout XML File

In the Layout File Name, type my_customlayout and click on Finish button.

On the top left panel, under project, go to app.

Right-click on App then select New => XML => Layout XML File

Configure Component window >> type my_customlayout >> click on Finish button. Configure Component window appears.

In the Layout File Name, type my_customlayout and click on Finish button.

Point to my_customlayout.xml A new file my_customlayout.xml is created.

In this we will create a custom view for the RecyclerView.

Point to LinearLayout In the Component Tree panel, we already have LinearLayout as root in the layout file.

The LinearLayout will stack the items either horizontally or vertically.

In the attribute panel, set the layout_height of LinearLayout to wrap_content. First, let us set the layout_height of LinearLayout to wrap_content in the Attribute panel.

wrap_content will expand or shrink according to the space required while adding the tools.

After this, the LinearLayout will only occupy height as much as it is required.

Next, we need to display thumbnail of each video in each list item.

So, now we will add an ImageView in the layout.

In the palette, type ImageView.

Drag and drop it on the Linear Layout in the component Tree.

In the Palette, search for ImageView.

Drag and drop it on the Linear Layout in the component Tree.

Open Drawable >> Project and select ic_launcher

Give a unique ID : video_thumbnail

A Resources dialog box opens.

On the left side, under Drawable, click Project, then select the image ic_launcher and click on OK button.

In the Attribute window, type video_thumbnail

in the ID field.

Next we need a TextView to show the title of the video.
Drag a TextView and drop it in the component tree on video_thumbnail.

Point to the image view

So, drag a TextView and drop it in the component tree on video_thumbnail.

The ImageView and TextView are embedded together.

In the output, we can see the thumbnail of the video in the

ImageView.

Point to Textview in the linear layout In LinearLayout, there are no constraints.

The Textview places itself in the LinearLayout.

Type video_title as unique ID

Change the textAppearance attribute of TextView to AppCompat.Display1

As a unique ID for the TextView we will type video_title.

Change the textAppearance attribute of TextView to AppCompat.Display1

The text will look larger now.

We need one more TextView to show the video level which are Basic, Intermediate and Advanced.
Add a TextView and give a unique ID as video_level Drag a TextView and drop it in the component tree on video_title.

As a unique ID to this TextView we will type video_level.

Change the orientation of my_customlayout.xml LinearLayout to vertical

Change its ID attribute to itemLinearLayout.

Click on the LinearLayout on the Component Tree.

In the Attributes window, change the orientation of LinearLayout to vertical.

This changes the TextView and ImageView orientation to vertical position.

Change its ID attribute to itemLinearLayout.

This ID will be used in on click listener method later.

Our custom layout is ready.

Change layout_width of ImageView to match_parent

layout_height to 200dp.

Next we’ll change the size of the image so that it looks larger.

So change the layout_width of ImageView to match_parent

We will also change the layout_height to 200dp.

We require an adapter to populate this custom layout in our RecyclerView now.
Click on app => java => com.example.searchapp

Right click on com.example.searchapp

Select New => Kotlin File/Class

Type name as MyAdapter and click on OK.

On the top left panel, under project,

Click on app=> java => com.example.spoken.searchapp

Right-click and select New => Kotlin File/Class

In the pop-up window, type the name as MyAdapter and click on OK button.

Point to MyAdapter.kt A new file gets created named MyAdapter.kt

In this, we will write the Kotlin code for the Adapter.

Go to MyAdapter.kt Type the below code.

What we have done is, we have created a class MyAdapter.

mContext is the context, that is the application which is used to fill the thumbnail images.

videoList will contain the list of all videos of type VideoItem class.

On compiling, the constructor for the values in the brackets, are created automatically.

So we don’t need to do that.

Point to the error The code shows error.

It is because we have not yet declared MyViewHolder class and implemented the required methods.

Copy- paste the code

class MyViewHolder(itemView : View) : RecyclerView.ViewHolder(itemView)

So first we will declare MyViewHolder class.

Type the code inside MyAdapter class as shown.

Copy- paste the code

Point to the code line as per narration

Now we will implement the required methods.

First we will create the onCreateViewHolder method.

Copy and paste the code for this method from the Code file myadapter.kt

Here we created a view having my_customlayout.xml and returned it through MyViewHolder class.

Copy- paste the code Now we will create the next required method which is onBindViewHolder.

Type the following code below onCreateViewHolder method.

Press Alt+Enter keys Press Alt+Enter keys and resolve the warnings.
Point as per narration We will use the position variable to know which item we are filling.

We first get the VideoItem object which is being filled currently in singleVideoItem.

Point as per narration Here we set the text of the video_title and video_level from the singleVideoItem’s values.
Next step is to fill the thumbnail image into the ImageView.

We can get the thumbnail from a specific spoken tutorial YouTube URL.

Point as per narration The URL has this format:

https://i.ytimg.com/vi/videoId/sddefault.jpg

So we will use the URL and pass the videoID for which we need the thumbnail image.

Point as per narration We have used Picasso, to load the image into video_thumbnail ImageView.
Point as per narration We have created setOnClickListener method for linear layout and named it as itemLinearLayout

When the thumbnail is clicked, it will play the YouTube video in the ThirdActivity.

Point as per narration We have not created the ThirdActivity and so it shows an error now.

We pass the videoID and videoTitle to the ThirdActivity by putExtra method.

Point as per narration We have added a required flag of Intent.FLAG_ACTIVITY_NEW_TASK.

This is required by YouTube activity.

Point as per narration Then we start the intent using mContext variable.
Copy- paste the code Type the next method getItemCount below onBindViewHolder method.
Point as per narration The function getItemCount returns the number of items to be shown inside RecyclerView.

The adapter code is completed now.

Let’s now create the third activity.
Project >> Right-click on app >> New >> Activity >> Empty activity On the top left panel, under project, go to app.

Right-click on app then select New -> Activity -> Empty Activity

Type name of the Activity as ThirdActivity Configure Activity window pops up.

Type the name of the Activity as ThirdActivity and click on the Finish button.

Wait for the process to finish.

Point to the line of code Go to MyAdapter.Kt

The error in our playVideoIntent code is resolved as we have created the ThirdActivity.

Next we will initialize the RecyclerView in SecondActivity.kt.
Go to SecondActivity.kt. Go to SecondActivity.kt.
Type the code before the volley code to initialize the RecyclerView.
Next we will create an object for MyAdapter.
Copy- paste the code Declare the variable globally so that we can use it in extractjson data method.

Type this code before onCreate method.

Copy- paste the code Now we will initialize the value of myAdapter variable inside oncreate method and after findViewById method

Copy paste the code from the code file Secondactivity.kt

Then set the required things to myRecyclerView as shown below.

myAdapter.notifyDataSetChanged() In the extractJsonData method, add the below line for notifying that the data has been received.

myAdapter.notifyDataSetChanged()

Click on ThirdActivity.kt Then go to ThirdActivity.kt
Point as per narration In onCreate method type this code.

Here we store the video ID and Title of the video that was clicked in second activity.

We will see a message with the video name that was clicked as output.
Run App Let us now run the App to see the output on the Android phone
Show the output on the phone Select the FOSS and Language and click on the Search button.

We can see that the video thumbnail loads on the next page.

Scroll down Scroll down to see all the thumbnails that are loaded for the selected FOSS and language.
Point as per narration Video title and level are displayed as well.

When we select a video the third activity opens.

It shows the selected video name as message.

This brings us to the end of this tutorial. Let us summarize.
Slide 8:

Summary

In this tutorial we learnt to
  • Use RecyclerView to display the thumbnail of videos.
  • Get the thumbnail from a specific Spoken Tutorial YouTube URL
  • Pass the videoID of the selected Spoken Tutorial
  • Run the Kotlin App and
  • Display the thumbnail of the selected video
Slide 9:

Assignment

As an assignment do the following.
  • Select a different FOSS and Language and check the thumbnails which are loaded.
Slide 10:

About Spoken Tutorial project

The video at the following link summarises the Spoken Tutorial project.

Please download and watch it

Slide 11:

About workshops

The Spoken Tutorial Project Team

conducts workshops and gives certificates on passing online tests.

For more details, please write to us.

Slide 12:

Forum for specific questions:

Please post your timed queries in this forum.
Slide 13:

Acknowledgement

Spoken Tutorial project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at

this link.

The Android app and the script for this tutorial was contributed by Abhishek Shah.

And this is Nirmala Venkat along with the Spoken Tutorial team from IIT Bombay, signing off.

Thanks for watching.

Contributors and Content Editors

Nancyvarkey, Nirmala Venkat