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HI, this is X-Raym, for the 7th part[br]of our ReaScript Course.

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In this episode, will wee learn how to get an item,[br]according to its position on its parent track.

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Imagine that I want to restrict our script[br]on items on selected tracks

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but still in time selection.

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I will have to get my items[br]in a different way.

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But before going further, I will clean the[br]script a bit by create a new functions.

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I will call it Action.

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I delete my warning messages,[br]we don't need it anymore.

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So <i>Main</i> here will check if our action[br]can be executed,

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And we will create a new function[br]called <i>Action</i>.

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I check if the script still works.

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It seems to work fine, I can[br]continue from here.

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I want to consider only[br]selected tracks.

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I will have to make a loop[br]from selected tracks.

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Count... sel... tracks...

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I search for the function...

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I paste it here.[br]The project is <i>0</i>.

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For every selected tracks...

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<i>count_sel_tracks - 1</i>

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<i>do</i>

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I add <i>end</i>

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For every track selected,

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we will get the track,

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"get sel track"

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This function to return a track

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according to it's index in selection.

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We already saw the equivalent function[br]for selected items.

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I put <i>j</i>

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The loop look for selected track.

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I will count the number of items they have.

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Count item

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<i>CountTrackMedialtems</i> which allows[br]to count the number of items on the track.

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I will create the variable[br]<i>count_items_on_tracks</i>

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Here, I have to put a track,

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and this track came from[br]my variable named <i>track</i>

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For every item on the track

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do the following thing,

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Get the item according to[br]it's index on the track.

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Here is the function.

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This track return an item according to[br]a track and a index on that track.

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The track still came[br]from the variable <i>track</i>,

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and the item index is defined by the loop[br]which starts here.

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So, I put <i>i</i>.

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I don't need this anymore.

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I can delete this.

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And all this is the same thing...

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Recap: the <i>Action</i> function will,[br]for every selected tracks,

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check all their items, and if an[br]item is inside the time selection

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then a new fade-out[br]length value will be set.

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This value came from the[br]item under mouse.

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I run the script to see.

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I set a fade here.

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And I check.

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We see that it does nothing.

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If I select this track,[br]the fade-out length value get propagated

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on items on selected tracks[br]which are in time selection.

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If I select this 3 tracks...

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We see that it works as expected.

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The loop could be a bit more optimized.

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Indeed, we don't need to check the items[br]that are after the time selection.

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I can do the following thing:

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<i>if</i>

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<i>If item_pos</i>

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is after the end of the time selection,

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<i>then</i>

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<i>break</i>, in other words[br]"Break the loop"

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<i>else</i>

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modify the items as desired.

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<i>Break</i> allows to stop on loop[br]so that it doesn't get executed unecessary.

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I will display <i>i</i>

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I will display <i>i</i> and <i>j</i> in the console.

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I duplicated some items,[br]and I run the script.

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As you can see, this doesn't consider the[br]other items (aka, beyond time selection).

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If I delete <i>break</i>,

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You can see that all items on selected[br]tracks have been unecessary checked.

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<i>Break</i> allows to save a bit of performance when[br]it is not necessary to calculate certain things.

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Our function check the first item,

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then the next item, and if its position is[br]after the end of time selection

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which means that every items after[br]this one will be in the same case,

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So no need to check their position and their[br]end to see if they are in time selection.

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In the next items, we will see how to use[br]a REAPER native function inside a script.