Android Advanced Road - Remove EditText inner margin

Just like the title, EditText in Android has its own padding. Generally speaking, setting the background to null is enough, but because of the use of an unfamiliar declarative framework, it took a few minutes to solve it, but it took a lot of time. half a day~

Simple requirements, related blog

• Android Advanced Road - Remove EditText inner margin
• The road to Android advancement - EditText input font adaptation

In fact, this is just a very simple small requirement. I didn’t want to but encountered some small problems. I simply spent some time to lay a solid foundation

trigger scene

This scene is exactly a UI effect that I need to adapt in my current development, so I wrote another Demo. After some tests, the summary is recorded here

my thinking

For the overall layout, the following two methods can be used (I tried both when the initial problem occurred, but I didn’t find the key to the problem at the time)

• Linear Vertical Layout + Frame Layout (EditText+TextView)
• Linear vertical layout + linear horizontal layout (EditText+TextView)

After the overall layout plan is finalized, it is mainly for EditTextroutine processing;

• It stands to reason that I only need to set background = null, but after setting, only the bottom line is removed, and the upper and lower margins still exist;
• I EditTextset a fixed height for , but EditTextthe display is incomplete (occluded), and the inner margin still exists and covers the input content

Because I'm using 声明式布局+splitties框架, I'm wondering if there are special settings in the framework? In order to eliminate the problem, I first tried the same processing method in xml, and found that the expected effect can be achieved; so the background = nullmethod is feasible, but it is not enough to meet our needs , and then I thought after a sleep: “既然是上下边距的问题，那去除内边距应该可以”, after trying finally adopted 设置 padding + backgroundthe method

我想现在采用这种布局方式的朋友应该还不是很多，故此留一份伪代码，用于各位了解我所遇场景和解决方式

Regarding troubleshooting, I checked whether the framework has been set internally, but it seems that the theme and the like are not set

Then I thought about looking at the source code of EditText, but the pursuit may not be right, and I will study it when I have time in the future

After searching, some people said that EditTextthe default backgroundis one InsetDrawable, InsetDrawableyou can search and learn about it by yourself, I will only make a simple record below

---

common scene

The following scenario is only my personal experience, from the original EditText effect -> remove the original default effect processing method and corresponding scenario

original scene

The original EditText without any settings, by default there will be底部线条+上下内边距

example

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="原始的EditText" />

---

Set the background scene

By setting EditText , backgroundyou can 去除其默认效果(margin and bottom horizontal line), I know that there are three common

• null (more commonly used)
• Color value
• drawable (can be a shape or a picture)

example

background = null

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:background="@null"
        android:hint="background 为 null" />

background = color value

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:background="#00000000"
        android:hint="background 为 色值" />

background = drawable

If the background image is not set, the background image height will be used by default

    <EditText
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_marginTop="10dp"
        android:background="@drawable/icon_font_bg"
        android:hint="background 为 drawable" />

---

set padding

Because the default effect has upper and lower margins, we can also achieve the basic effect by setting padding

Only set padding

When only padding is set, the default bottom line will not disappear

example

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:hint="padding 为 0"
        android:padding="0dp" />

---

set padding + background

我所遇到的问题，就是通过这种方式达到理想效果的

example

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@null"
        android:hint="padding=0 + background=null"
        android:padding="0dp" />

---

demo test

This is the demo I used to test EditTextthe display scene, memo here

Effect

xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="原始的EditText" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:background="@null"
        android:hint="background 为 null" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:background="#00000000"
        android:hint="background 为 色值" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_marginTop="10dp"
        android:background="@drawable/icon_font_bg"
        android:hint="background 为 drawable" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:hint="padding 为 0"
        android:padding="0dp" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:background="null"
        android:hint="padding=0 + background=null"
        android:padding="0dp" />

</androidx.appcompat.widget.LinearLayoutCompat>