Como posso fazer algo como um FlowLayout no Android?

Como posso fazer algo como FlowLayoutno Android?

Se você assistir à palestra que dei no dia da Devoxx University (disponível em parleys.com ), você aprenderá a fazer isso sozinho. Durante a palestra eu escrevi umFlowLayout implementação ao vivo no palco para mostrar como é simples escrever layouts personalizados.

A implementação está hospedada aqui .

Você deve usar FlexboxLayoutcom flexWrap="wrap"atributo.

<com.google.android.flexbox.FlexboxLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     app:flexWrap="wrap">

<!-- contents go here -->

</com.google.android.flexbox.FlexboxLayout>

Para obter instruções de compilação, consulte o repositório github.

Mais sobre isso - https://android-developers.googleblog.com/2017/02/build-flexible-layouts-with.html

Não tenho reputação suficiente para postar um comentário sobre a resposta de Romain Guy, mas é onde esta resposta deve estar (criei uma conta apenas para compartilhar minha edição).

De qualquer forma, vejo que outras pessoas descobriram que sua solução FlowLayout muito legal tem alguns problemas. Eu próprio consegui encontrar um e vi, como outros, que algumas crianças foram cortadas. Olhando em detalhes no algoritmo, parece ser um erro muito simples no cálculo da altura. Quando o último filho é aquele que está sendo colocado em uma nova linha, a altura não foi computada corretamente. Limpei um pouco o cálculo (havia um uso estranho de "altura" vs. altura atual).

A seguinte alteração corrige o problema de "o último filho é cortado se estiver em uma nova linha":

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
    int widthLimit = MeasureSpec.getSize(widthMeasureSpec) - getPaddingRight();
    int widthMode = MeasureSpec.getMode(widthMeasureSpec);

    boolean growHeight = widthMode != MeasureSpec.UNSPECIFIED;

    int width = 0;

    int currentWidth = getPaddingLeft();
    int currentHeight = getPaddingTop();

    int maxChildHeight = 0;

    boolean breakLine = false;
    boolean newLine = false;
    int spacing = 0;

    final int count = getChildCount();
    for (int i = 0; i < count; i++)
    {
        View child = getChildAt(i);
        measureChild(child, widthMeasureSpec, heightMeasureSpec);

        LayoutParams lp = (LayoutParams) child.getLayoutParams();
        spacing = mHorizontalSpacing;

        if (lp.horizontalSpacing >= 0)
        {
            spacing = lp.horizontalSpacing;
        }

        if (growHeight && (breakLine || ((currentWidth + child.getMeasuredWidth()) > widthLimit)))
        {               
            newLine = true;
            currentHeight += maxChildHeight + mVerticalSpacing;

            width = Math.max(width, currentWidth - spacing);

            currentWidth = getPaddingLeft();
            maxChildHeight = 0;
        }
        else
        {
            newLine = false;
        }

        maxChildHeight = Math.max(maxChildHeight, child.getMeasuredHeight());

        lp.x = currentWidth;
        lp.y = currentHeight;

        currentWidth += child.getMeasuredWidth() + spacing;

        breakLine = lp.breakLine;
    }

    if (newLine == false)
    {
        width = Math.max(width, currentWidth - spacing);
    }

    width += getPaddingRight();
    int height = currentHeight + maxChildHeight + getPaddingBottom();

    setMeasuredDimension(resolveSize(width, widthMeasureSpec),
            resolveSize(height, heightMeasureSpec));
}

Existe uma biblioteca do Google, chamada "flexbox-layout" . Você deveria dar uma olhada.

Para usá-lo no RecyclerView, você pode usar algo assim:

val layoutManager = FlexboxLayoutManager(activity)
layoutManager.flexDirection = FlexDirection.ROW
layoutManager.flexWrap = FlexWrap.WRAP
layoutManager.justifyContent = JustifyContent.FLEX_START
layoutManager.alignItems = AlignItems.FLEX_START 
recyclerView.layoutManager=layoutManager

Como uma das respostas anteriores, comecei com a solução aqui: http://hzqtc.github.io/2013/12/android-custom-layout-flowlayout.html

Eu o estendi para explicar as diferentes alturas das crianças, conforme abaixo.

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

// Custom layout that wraps child views to a new line
public class FlowLayout extends ViewGroup {

    private int marginHorizontal;
    private int marginVertical;

    public FlowLayout(Context context) {
        super(context);
        init();
    }

    public FlowLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() { // Specify the margins for the children
        marginHorizontal = getResources().getDimensionPixelSize(R.dimen.activity_half_horizontal_margin);
        marginVertical = getResources().getDimensionPixelSize(R.dimen.activity_half_vertical_margin);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lowestBottom = 0;
        int lineHeight = 0;
        int myWidth = resolveSize(100, widthMeasureSpec);
        int wantedHeight = 0;

        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }

            child.measure(getChildMeasureSpec(widthMeasureSpec, 0, child.getLayoutParams().width),
                    getChildMeasureSpec(heightMeasureSpec, 0, child.getLayoutParams().height));
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();
            lineHeight = Math.max(childHeight, lineHeight);

            if (childWidth + childLeft + getPaddingRight() > myWidth) { // Wrap this line
                childLeft = getPaddingLeft();
                childTop = marginVertical + lowestBottom; // Spaced below the previous lowest point
                lineHeight = childHeight;
            }
            childLeft += childWidth + marginHorizontal;

            if (childHeight + childTop > lowestBottom) { // New lowest point
                lowestBottom = childHeight + childTop;
            }
        }

        wantedHeight += childTop + lineHeight + getPaddingBottom();
        setMeasuredDimension(myWidth, resolveSize(wantedHeight, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lowestBottom = 0;
        int myWidth = right - left;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();

            if (childWidth + childLeft + getPaddingRight() > myWidth) { // Wrap this line
                childLeft = getPaddingLeft();
                childTop = marginVertical + lowestBottom; // Spaced below the previous lowest point
            }
            child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
            childLeft += childWidth + marginHorizontal;

            if (childHeight + childTop > lowestBottom) { // New lowest point
                lowestBottom = childHeight + childTop;
            }
        }
    }
}

Usei isso como uma solução para agrupar TextEdits de várias linhas. Espero que ajude!

Aqui está a classe personalizada onde você pode obter um layout como seguir com a adição de visualização dinâmica (também chamado de FlowLayout).

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/*
Created By Dhavalkumar Solanki
* */
public class FlowLayout extends ViewGroup {

    private int line_height_space;

    public static class LayoutParams extends ViewGroup.LayoutParams {

        public int horizontal_spacing;
        public int vertical_spacing;

        /**
         * @param horizontal_spacing Pixels between items, horizontally
         * @param vertical_spacing   Pixels between items, vertically
         */
        public LayoutParams(int horizontal_spacing, int vertical_spacing) {
            super(0, 0);
            this.horizontal_spacing = horizontal_spacing;
            this.vertical_spacing = vertical_spacing;
        }
    }

    public FlowLayout(Context context) {
        super(context);
    }

    public FlowLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

        final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
        int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
        final int count = getChildCount();
        int line_height_space = 0;

        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        int childHeightMeasureSpec;
        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
        } else {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        }


        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
                final int childw = child.getMeasuredWidth();
                line_height_space = Math.max(line_height_space, child.getMeasuredHeight() + lp.vertical_spacing);

                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height_space;
                }

                xpos += childw + lp.horizontal_spacing;
            }
        }
        this.line_height_space = line_height_space;

        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
            height = ypos + line_height_space;

        } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            if (ypos + line_height_space < height) {
                height = ypos + line_height_space;
            }
        }
        setMeasuredDimension(width, height);
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(1, 1); // default of 1px spacing
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        if (p instanceof LayoutParams) {
            return true;
        }
        return false;
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int count = getChildCount();
        final int width = r - l;
        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final int childw = child.getMeasuredWidth();
                final int childh = child.getMeasuredHeight();
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height_space;
                }
                child.layout(xpos, ypos, xpos + childw, ypos + childh);
                xpos += childw + lp.horizontal_spacing;
            }
        }
    }
}

Exemplo:

text_view.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tool="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="5dp">

    <TextView
        android:id="@+id/tvText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="19sp"
        android:background="@drawable/unselected_tag"
        android:textColor="@color/colorPrimary"
        tool:text="Temp" />
</RelativeLayout>

activity_flow_layou_demo.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    >
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/tvTitleBusiness"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="Business Interest "
                    android:textColor="@color/colorPrimary"
                    android:textSize="25sp" />

                <com.example.tristateandroid2.radardemo.FlowLayout
                    android:id="@+id/flowBusiness"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                </com.example.tristateandroid2.radardemo.FlowLayout>
            </LinearLayout>

            <LinearLayout
                android:layout_marginTop="@dimen/activity_horizontal_margin"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/tvTitlePrivate"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="Private Interest "
                    android:textColor="@color/colorPrimary"
                    android:textSize="25sp" />

                <com.example.tristateandroid2.radardemo.FlowLayout
                    android:id="@+id/flowPrivate"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                </com.example.tristateandroid2.radardemo.FlowLayout>
            </LinearLayout>
        </LinearLayout>
    </ScrollView>
</RelativeLayout>

FlowLayouDemo.java

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;

import java.util.ArrayList;

public class FlowLayouDemo extends AppCompatActivity {
    private TextView tvTitleBusiness;
    private FlowLayout flowBusiness;
    private TextView tvTitlePrivate;
    private FlowLayout flowPrivate;
    private ArrayList<TagModel> arrayList;

    private void findViews() {
        tvTitleBusiness = (TextView) findViewById(R.id.tvTitleBusiness);
        flowBusiness = (FlowLayout) findViewById(R.id.flowBusiness);
        tvTitlePrivate = (TextView) findViewById(R.id.tvTitlePrivate);
        flowPrivate = (FlowLayout) findViewById(R.id.flowPrivate);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_flow_layou_demo);
        findViews();
        addLayouts();
    }

    private void addLayouts() {
        if (arrayList == null) {
            arrayList = new ArrayList<>();
        }
        flowBusiness.removeAllViews();
        flowPrivate.removeAllViews();
        for (int i = 0; i < 75; i++) {

            final boolean[] selected = {false};
            View view = this.getLayoutInflater().inflate(R.layout.text_view, null);
            final TextView textView = (TextView) view.findViewById(R.id.tvText);
            if (i % 5 == 0) {
                arrayList.add(new TagModel(i, false, "Business VIEW : " + i));
                textView.setText("Busi VIEW To  IS : " + i);
            } else {
                arrayList.add(new TagModel(i, false, "TEXT IS : " + i));
                textView.setText("Busi IS : " + i);
            }
            textView.setBackgroundResource(R.drawable.unselected_tag);
            textView.setTextColor(Color.parseColor("#3F51B5"));
            textView.setTag(i);
            if(i<=50){
                flowBusiness.addView(view);
            }else {
                textView.setText("Priv View : "+i);
                flowPrivate.addView(view);
            }

            textView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if (selected[0]) {
                        selected[0] = false;
                        textView.setBackgroundResource(R.drawable.unselected_tag);
                        textView.setTextColor(Color.parseColor("#3F51B5"));
                    } else {
                        selected[0] = true;
                        textView.setBackgroundResource(R.drawable.selected_tag);
                        textView.setTextColor(Color.parseColor("#FFFFFF"));
                    }
                }
            });

        }
    }
}

Uma revisão para @MattNotEquals () FlowLayout que oferece suporte a MarginLayoutParams.

Esta é apenas uma implementação minimalista de MarginLayoutParms para oferecer suporte às margens esquerda, direita, superior e inferior.

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/**
 *  Original version courtesy of MattNotEquals() at http://stackoverflow.com/a/34169798/4515489 - 4/13/17.
 *  7/15/17 Revised to support MarginLayoutParams.
 */
public class FlowLayout extends ViewGroup {
    // Custom layout that wraps child views to a new line.

    public FlowLayout(Context context) {
        super(context);
    }

    public FlowLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lowestBottom = 0;
        int lineHeight = 0;
        int myWidth = resolveSize(100, widthMeasureSpec);
        int wantedHeight = 0;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }
            child.measure(getChildMeasureSpec(widthMeasureSpec, 0, child.getLayoutParams().width),
                          getChildMeasureSpec(heightMeasureSpec, 0, child.getLayoutParams().height));
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();
            lineHeight = Math.max(childHeight, lineHeight);

            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            childLeft += lp.leftMargin;
            childTop += lp.topMargin;
            if (childLeft + childWidth + lp.rightMargin + getPaddingRight() > myWidth) { // Wrap this line
                childLeft = getPaddingLeft() + lp.leftMargin;
                childTop = lowestBottom + lp.topMargin; // Spaced below the previous lowest point
                lineHeight = childHeight;
            }
            childLeft += childWidth + lp.rightMargin;

            if (childTop + childHeight + lp.bottomMargin > lowestBottom) { // New lowest point
                lowestBottom = childTop + childHeight + lp.bottomMargin;
            }
        }
        wantedHeight += lowestBottom + getPaddingBottom(); // childTop + lineHeight + getPaddingBottom();
        setMeasuredDimension(myWidth, resolveSize(wantedHeight, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lowestBottom = 0;
        int myWidth = right - left;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();

            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            childLeft += lp.leftMargin;
            childTop += lp.topMargin;
            if (childLeft + childWidth + lp.rightMargin + getPaddingRight() > myWidth) { // Wrap this line
                childLeft = getPaddingLeft() + lp.leftMargin;
                childTop = lowestBottom + lp.topMargin; // Spaced below the previous lowest point
            }
            child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
            childLeft += childWidth + lp.rightMargin;

            if (childTop + childHeight + lp.bottomMargin > lowestBottom) { // New lowest point
                lowestBottom = childTop + childHeight + lp.bottomMargin;
            }
        }
    }

    @Override
    public boolean shouldDelayChildPressedState() {
        return false;
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        return p instanceof LayoutParams;
    }

    @Override
    protected LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    }

    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new FlowLayout.LayoutParams(getContext(), attrs);
    }

    @Override
    protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) {
        if (lp instanceof LayoutParams) {
            return new LayoutParams((LayoutParams) lp);
        }
        else if (lp instanceof MarginLayoutParams) {
            return new LayoutParams((MarginLayoutParams) lp);
        }
        else
            return super.generateLayoutParams(lp);
    }

    /**
     * Per-child layout information for layouts that support margins.
     */
    public static class LayoutParams extends MarginLayoutParams {
        public LayoutParams(@NonNull Context c, @Nullable AttributeSet attrs) {
            super(c, attrs);
        }
        public LayoutParams(int width, int height) {
            super(width, height);
        }
        public LayoutParams(@NonNull ViewGroup.LayoutParams source) {
            super(source);
        }
        public LayoutParams(@NonNull ViewGroup.MarginLayoutParams source) {
            super(source);
        }
        public LayoutParams(@NonNull LayoutParams source) {
            super(source);
        }
    }
}

Bom código FlowLayout autocontido simples aqui (apenas alguns arquivos gist.github concisos) :

http://hzqtc.github.io/2013/12/android-custom-layout-flowlayout.html

No entanto, a atividade pronta para uso não funcionou para eu carregar o layout personalizado.

Eu encontrei esta solução [usando a chamada .inflate () de 2 parâmetros deste exemplo ] :

@Override
protected void onCreate(Bundle savedInstanceState)
{
    // ..

    setContentView(R.layout.main_res_layout_activity_main);

    ViewGroup flowContainer = getFlowLayoutView(); 

    // ..
}

ViewGroup getFlowLayoutView()
{
    LayoutInflater inflater = getLayoutInflater();

    ViewGroup flowLayout = 
        (ViewGroup)
            inflater.inflate(
                    R.layout.main_res_layout_activity_main,
                    (FlowLayout) findViewById(R.id.flow_container)
            );

    return flowLayout;
}

Agora há suporte integrado no ConstraintLayout usando um widget de fluxo. Ele tem muitas opções que podem ser usadas para atingir vários tipos de fluxos.

Exemplo:

<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">

<androidx.constraintlayout.helper.widget.Flow
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    app:constraint_referenced_ids="item_1,item_2,item_3"
    app:flow_horizontalBias="0"
    app:flow_horizontalGap="10dp"
    app:flow_horizontalStyle="packed"
    app:flow_verticalGap="8dp"
    app:flow_wrapMode="aligned"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<View
    android:id="@+id/item_1"
    android:layout_width="50dp"
    android:layout_height="50dp" />

<View
    android:id="@+id/item_2"
    android:layout_width="50dp"
    android:layout_height="50dp" />

<View
    android:id="@+id/item_3"
    android:layout_width="50dp"
    android:layout_height="50dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

Dê uma olhada nesta postagem: https://medium.com/@tapanrgohil/constraintlayout-flow-bye-bye-to-linerlayout-78fd7fa9b679

E aqui: https://www.bignerdranch.com/blog/constraintlayout-flow-simple-grid-building-without-nested-layouts/