Create tag cloud
I need to create a basic tag cloud ... My goal is to add multiple TextViews (tags) that will automatically fit onto a new line if the number exceeds the width of the device. (Similar to Instagram).
Right now, when the width of the layout containing ( TextView ) exceeds ( device width ) the TextView (s) at the end wraps itself.
I tried using RelativeLayout, but I can't figure out the logic. I've looked over this one , but if there is a better or just a cleaner solution.
Thanks for your precious time.
There is no need for the result to look like Instagram.
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A cleaner solution is to create your own ViewGroup class. Find a sample below.
For a full descriptive explanation, visit How to Create a Custom Layout in Android by Extending the ViewGroup Class .
public class TagLayout extends ViewGroup {
public TagLayout(Context context) {
super(context);
}
public TagLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public TagLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int count = getChildCount();
int curWidth, curHeight, curLeft, curTop, maxHeight;
//get the available size of child view
final int childLeft = this.getPaddingLeft();
final int childTop = this.getPaddingTop();
final int childRight = this.getMeasuredWidth() - this.getPaddingRight();
final int childBottom = this.getMeasuredHeight() - this.getPaddingBottom();
final int childWidth = childRight - childLeft;
final int childHeight = childBottom - childTop;
maxHeight = 0;
curLeft = childLeft;
curTop = childTop;
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() == GONE)
return;
//Get the maximum size of the child
child.measure(MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.AT_MOST));
curWidth = child.getMeasuredWidth();
curHeight = child.getMeasuredHeight();
//wrap is reach to the end
if (curLeft + curWidth >= childRight) {
curLeft = childLeft;
curTop += maxHeight;
maxHeight = 0;
}
//do the layout
child.layout(curLeft, curTop, curLeft + curWidth, curTop + curHeight);
//store the max height
if (maxHeight < curHeight)
maxHeight = curHeight;
curLeft += curWidth;
}
}
}
To use TagLayout, you can add it to your activity / fragment description declaration. main_activity.xml
<com.javatechig.taglayout.TagLayout
android:id="@+id/tagLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
We can now have a custom view that allows us to set a certain level of customization for each tag layout.
tag_layout.xml
<TextView
android:id="@+id/tagTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:background="#a000"
android:padding="10dp"
android:textColor="#fff" />
MainActivity.java Finally, from the activity class, you can add tag elements as follows.
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TagLayout tagLayout = (TagLayout) findViewById(R.id.tagLayout);
LayoutInflater layoutInflater = getLayoutInflater();
String tag;
for (int i = 0; i <= 20; i++) {
tag = "#tag" + i;
View tagView = layoutInflater.inflate(R.layout.tag_layout, null, false);
TextView tagTextView = (TextView) tagView.findViewById(R.id.tagTextView);
tagTextView.setText(tag);
tagLayout.addView(tagView);
}
}
}
Result
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I believe the solution above always takes into account the full width of the screen, so if a developer sets a parameter android:layout_width
, for example, it will not respect its value or even the parent field and additional values.
I fixed it like this:
private int mScreenWidth = 0;
private int mAvailableWidth = -1;
public TagLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
private void init(Context context) {
Display display = ((WindowManager)context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
Point deviceSize = new Point();
display.getSize(deviceSize);
mScreenWidth = deviceSize.x;
}
private void calculateAvailableWidth() {
if(getLayoutParams() != null && getLayoutParams().width > 0) {
mAvailableWidth = getLayoutParams().width;
return;
}
mAvailableWidth = mScreenWidth;
ViewGroup parent = this;
while(parent != null) {
mAvailableWidth -= parent.getPaddingLeft() + parent.getPaddingRight();
if(parent.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
ViewGroup.MarginLayoutParams layoutParams = (ViewGroup.MarginLayoutParams)parent.getLayoutParams();
mAvailableWidth -= layoutParams.leftMargin + layoutParams.rightMargin;
}
if(parent.getParent() instanceof ViewGroup)
parent = (ViewGroup)parent.getParent();
else
parent = null;
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int count = getChildCount();
int currentRowWidth = 0;
int currentRowHeight = 0;
int maxItemWidth = 0;
int maxWidth = 0;
int maxHeight = 0;
if(mAvailableWidth == -1)
calculateAvailableWidth();
for(int i = 0; i < count; i++) {
View child = getChildAt(i);
if(child.getVisibility() == GONE)
continue;
try {
measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, 0);
}
catch(Exception e) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
int childWidth = child.getMeasuredWidth() + child.getPaddingRight() + child.getPaddingLeft();
int childHeight = child.getMeasuredHeight() + child.getPaddingTop() + child.getPaddingBottom();
maxItemWidth = Math.max(maxItemWidth, childWidth);
if(currentRowWidth + childWidth < mAvailableWidth) {
currentRowWidth += childWidth;
maxWidth = Math.max(maxWidth, currentRowWidth);
currentRowHeight = Math.max(currentRowHeight, childHeight);
}
else {
currentRowWidth = childWidth;
maxHeight += currentRowHeight;
}
}
if(getLayoutParams().width == LayoutParams.WRAP_CONTENT) {
mAvailableWidth = maxItemWidth;
maxWidth = maxItemWidth;
}
maxHeight += currentRowHeight + getPaddingTop() + getPaddingBottom();
setMeasuredDimension(maxWidth, maxHeight);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
int count = getChildCount();
int currentLeft = getPaddingLeft();
int currentTop = getPaddingTop();
int currentRight;
int currentBottom;
int parentWidth = this.getPaddingRight() - this.getPaddingLeft() + right;
for(int i = 0; i < count; i++) {
View child = getChildAt(i);
if(child.getVisibility() == View.GONE)
return;
int currentWidth = child.getMeasuredWidth() + child.getPaddingRight() + child.getPaddingLeft();
int currentHeight = child.getMeasuredHeight() + child.getPaddingBottom() + child.getPaddingTop();
if(currentLeft + currentWidth > parentWidth) {
currentLeft = getPaddingLeft();
currentTop += currentHeight;
}
currentBottom = currentTop + currentHeight;
currentRight = currentLeft + currentWidth;
child.layout(currentLeft, currentTop, currentRight, currentBottom);
currentLeft += currentWidth;
}
}
So you can set android:layout_width="250dp"
and get a result like this:
Install android:layout_width="match_parent"
and get the result like this:
Or use event android:layout_width="wrap_content
and get the result like this:
Hope it helps.
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