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all right so let's see if our

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application works before we continue

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adding more code I'm just going to start

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my emulator and I'll just fast forward

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this until it's are loaded

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all right so emulator started so let's

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run the application and just test this

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out so want to make sure that all ten of

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the numeric buttons work and also the

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dock button and we're going to test it

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in landscape as well that's particularly

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important here because we're using a

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different layout for landscape all right

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so let's start there digits seven eight

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nine four five six one two three zero

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and click on the dot and I shouldn't be

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able to click on the dot again that's

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correct

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so all ten of the digit buttons work and

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the decimal point will only work once

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and the reason for that by the way is

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because we set the edit text to number

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decimal in the layout an android takes

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care of only allowing a single full stop

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to be entered which saves us from having

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to worry about checking the validity of

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the number that's entered now if your

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dot button doesn't work check the layout

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if you made the edit takes just a number

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signed in the layout then it won't

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accept the decimal point you need that

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number decimal as well alright so let's

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quickly check landscapes working as well

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so I'm going to just delete this delete

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those numbers again seven eight nine

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four five six one two three zero dot and

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I can't press the dock more than once so

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that's actually working well alright so

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let's go back to the code now there's

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still a bit of validation that we have

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to code but so we're going to come back

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to that later the moment though the

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buttons are doing something in our

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onclicklistener is working nicely so at

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this point is now time to create the own

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click listener for the operation buttons

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now once again we're going to be passing

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the actual view that causes the onclick

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to be called so we'll read its text to

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work out which operation it represents

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I'm going to type the code in first and

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then we'll go through this afterwards

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we're going to do that below our button

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code our set on click listeners for our

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button code so valves base open listener

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because view with a capital v dot on

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click listener then we've got a left or

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right curly braces and V dash greater

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than sign then it's going to talk about

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we're taught vowel space Opie

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Eckles in parentheses vs button capital

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B there dot text dot teach string and

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now value equals new number dot text

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that should be dr. string then I'm going

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to type if the next line parenthesis

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value done is not empty ending

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parenthesis and open a code block so

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that's the case we're going to perform

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operation value comma space o P and we

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haven't written that function yet so

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we're getting an error then outside of

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the order closing code block pending

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operation it was ap then on the last

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line to supply operation dot txt is

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equal two pending operation right this

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starts off very similar to what we've

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just done for the number buttons we

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create a new instance of onclicklistener

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and we saw in the instance to a variable

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called open listener that's on line 64

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now this method casts the do us a button

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then reads the text and assigns it to

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the string of variable opie on line 65

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and it also reads the number from the

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edit text widget new number and you can

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see it doing that on line 66 now there

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may not actually be any text though and

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there's nothing to stop the user from

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pressing in operation button before one

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of the numbers so before calling the

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perform operation method we're checking

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that the string is an empty on line 67

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now if there was something entered

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perform operation is called and that's

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the line that's currently showing an

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error because we haven't written that

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function yet but that's fine we won't we

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know we will need it just don't try to

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run the code until it's written because

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obviously it won't compile now whether

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perform operation was called or not the

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operation that got us here is near the

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pending operation and we're going to

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display that on the screen in the

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display operation textview and we're

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doing that on line 71 so all that

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remains is to assign the listener to the

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five buttons and at that point we've

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completed the first flowchart that we

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looked at in the previous video so let's

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go ahead and do that so it's going to be

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button equals

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doc said onclicklistener and it's going

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to be opener let's do the other ones as

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well we've got the divide multiply minus

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and plus then for each side miners we've

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got our multiplier and if you just do me

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consistent limits you have been divided

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multiplied at them with our miners on

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this line doesn't really matter so long

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as we've got all the buttons set up in

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this fashion so equals divide multiply

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minus and plus have all been assigned

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the only listener alright so we can't

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test it yet until we fix this or create

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this function and that perform operation

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method has a bit of work to do but so

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that we can test the program so far

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let's go ahead and create a dummy method

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that just displays the operation in the

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textview I'm gonna come down here

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private I'm saying method but obviously

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it's a function so private fail perform

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operation it's going to be in

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parentheses value colon string come up

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then we're going to have operation colon

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space and a string and we're just going

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to keep it pretty simple at the moment

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to supply operation dot text equals

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operation so it's just basically a dummy

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dummy method that displays the operation

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in the textview but it clears the error

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so that we can test our program again so

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if we actually run this again now go

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back to our emulator this time the

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numbers and decimal point should still

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work and when we press one of the

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operate the operations buttons they

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should be shown on the screen so we can

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still enter a couple of numbers here but

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then if I press some of the operations

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buttons there's our divide multiply

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minus plus equals they were working

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nicely and obviously we can enter other

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numbers as well and this the dot is

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where here's it should be so so far so

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good

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so let's finish this video here now and

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in the next video we're gonna get the

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perform operation method to perform the

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appropriate calculations so I'll see you

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in that next video