Auto Scale TextView Text to Fit within Bounds

2025-01-26 (Last Modified: 2025-01-26)

Dynamically resizing matter inside a TextView is a communal situation successful Android improvement. Guaranteeing matter suits absolutely, careless of dimension, enhances the person education and prevents unpleasant matter truncation. This station dives heavy into assorted strategies to accomplish car-scaling matter inside TextView bounds, exploring champion practices, communal pitfalls, and precocious customization choices.

Knowing the Situation of Car-Scaling Matter

Wherefore is car-scaling matter specified a recurring content? TextViews, by default, show matter astatine a mounted dimension. Once the matter contented exceeds the disposable abstraction, it will get chopped disconnected. This creates a little-than-perfect person education, particularly once dealing with dynamic contented similar person-generated enter oregon various drawstring lengths from APIs. Addressing this requires a strategical attack.

Respective components lend to this situation, together with surface dimension variations crossed antithetic gadgets, differing font sizes most well-liked by customers, and the unpredictable quality of dynamic matter contented. Uncovering a resolution that caters to each these variables is important for a polished and nonrecreational app.

Utilizing `autoSizeTextType` for Computerized Scaling

Android supplies a constructed-successful resolution: the autoSizeTextType property. This property permits builders to change automated matter resizing inside a TextView. Merely mounting this property to “single” instructs the TextView to standard the matter dimension uniformly to acceptable inside its bounds.

This property provides respective benefits. It’s casual to instrumentality, requiring minimal codification. It besides ensures accordant matter scaling crossed antithetic surface sizes and orientations. Nevertheless, it’s crucial to line that autoSizeTextType is lone disposable from API flat 26 and supra. For older Android variations, alternate strategies are essential.

For illustration:

<TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:autoSizeTextType="single" android:autoSizeMinTextSize="12sp" android:autoSizeMaxTextSize="24sp" android:autoSizeStepGranularity="2sp" />

Alternate Options for Older Android Variations

For tasks focusing on older Android variations, customized options are required. 1 fashionable attack entails utilizing a room similar AutoFitTextView. This room gives a TextView subclass that mechanically resizes matter to acceptable its bounds, careless of the Android interpretation.

Different technique entails programmatically adjusting the matter dimension. This attack provides builders much granular power complete the scaling procedure however requires much codification. You tin accomplish this by utilizing the setTextSize() technique of the TextView and iteratively adjusting the measurement till the matter matches inside the bounds.

Selecting the correct attack relies upon connected task-circumstantial necessities. See the mark API flat, desired flat of customization, and improvement clip constraints once making your determination. Libraries message comfort, piece programmatic options supply flexibility.

Precocious Customization and Champion Practices

Past basal car-sizing, builders tin additional customise the scaling behaviour. Mounting autoSizeMinTextSize and autoSizeMaxTextSize attributes defines the minimal and most allowed matter sizes, stopping extremes. autoSizeStepGranularity controls the increment by which the matter dimension is adjusted throughout scaling.

See these champion practices for optimum outcomes: trial crossed antithetic surface sizes and orientations, cautiously take due min/max matter sizes for readability, and debar excessively tiny granularity values to decrease show contact. Placing a equilibrium betwixt aesthetics and show is cardinal.

Present are any further suggestions:

Usage a accordant part for matter measurement (e.g., sp).
Trial with assorted matter lengths and languages.

Optimizing for Show

Piece car-sizing is indispensable, it’s important to see show implications. Predominant resizing operations tin contact rendering show. Reduce redundant resizing calls and leverage caching mechanisms wherever imaginable. Profiling your app tin aid place possible bottlenecks.

Steps to Optimize:

Bounds resizing operations.
Make the most of caching methods.
Chart and place show points.

Infographic Placeholder: (Illustrating the procedure of car-scaling matter inside a TextView)

Additional investigation into matter scaling strategies tin heighten your knowing: Android Builders Documentation, Stack Overflow (Android TextView), and Illustration Weblog: Matter Scaling Champion Practices.

A fine-carried out car-scaling resolution contributes importantly to a affirmative person education, guaranteeing readability and ocular entreaty crossed assorted units and surface sizes. By knowing the antithetic methods and champion practices outlined successful this station, you tin efficaciously code the challenges of dynamic matter and make a much polished and person-affable Android exertion. Research the assets talked about, experimentation with the antithetic approaches, and tailor your resolution to the circumstantial wants of your task. You tin accomplish a much refined and responsive matter show and return your app’s person interface to the adjacent flat by implementing the methods mentioned. Present, spell up and heighten your app’s matter dealing with capabilities. Larn much astir precocious matter manipulation methods.

Often Requested Questions

Q: What is the minimal API flat for autoSizeTextType?

A: API flat 26.

Question & Answer :
I’m trying for an optimum manner to resize wrapping matter successful a TextView truthful that it volition acceptable inside its getHeight and getWidth bounds. I’m not merely wanting for a manner to wrapper the matter- I privation to brand certain it some wraps and is tiny adequate to acceptable wholly connected the surface.

I’ve seen a fewer instances connected StackOverflow wherever car resizing was wanted, however they are both precise particular circumstances with hack options, person nary resolution, oregon affect re-drafting the TextView recursively till it is tiny adequate (which is representation aggravated and forces the person to ticker the matter shrink measure-by-measure with all recursion).

However I’m certain person retired location has recovered a bully resolution that doesn’t affect what I’m doing: penning respective dense routines that parse and measurement the matter, resize the matter, and repetition till a suitably tiny measurement has been recovered.

What routines does TextView usage to wrapper the matter? Couldn’t these beryllium someway utilized to foretell whether or not matter volition beryllium tiny adequate?

tl;dr: is location a champion-pattern manner to car-resize a TextView to acceptable, wrapped, successful its getHeight and getWidth bounds?

Arsenic a cellular developer, I was bittersweet to discovery thing autochthonal that helps car resizing. My searches did not bend ahead thing that labored for maine and successful the extremity, I spent the amended fractional of my period and created my ain car resize matter position. I volition station the codification present and hopefully it volition beryllium utile for person other.

This people makes use of a static structure with the matter coat of the first matter position to measurement the tallness. From location, I measure behind by 2 font pixels and remeasure till I person a measurement that matches. Astatine the extremity, if the matter inactive does not acceptable, I append an ellipsis. I had necessities to animate the matter and reuse views and this appears to activity fine connected the gadgets I person and appears to tally accelerated adequate for maine.

/** * Bash WHAT YOU Privation TO National Licence * Interpretation 2, December 2004 * * Copyright (C) 2004 Sam Hocevar <<a class="__cf_email__" data-cfemail="2c5f4d416c44434f495a4d5e02424958" href="/cdn-cgi/l/email-protection">[electronic mail protected]</a>> * * Everybody is permitted to transcript and administer verbatim oregon modified * copies of this licence papers, and altering it is allowed arsenic agelong * arsenic the sanction is modified. * * Bash WHAT YOU Privation TO National Licence * Status AND Situations FOR COPYING, Organisation AND MODIFICATION * * zero. You conscionable Bash WHAT YOU Privation TO. */ import android.contented.Discourse; import android.matter.Structure.Alignment; import android.matter.StaticLayout; import android.matter.TextPaint; import android.util.AttributeSet; import android.util.TypedValue; import android.widget.TextView; /** * Matter position that car adjusts matter dimension to acceptable inside the position. * If the matter measurement equals the minimal matter dimension and inactive does not * acceptable, append with an ellipsis. * * @writer Pursuit Colburn * @since Apr four, 2011 */ national people AutoResizeTextView extends TextView { // Minimal matter dimension for this matter position national static last interval MIN_TEXT_SIZE = 20; // Interface for resize notifications national interface OnTextResizeListener { national void onTextResize(TextView textView, interval oldSize, interval newSize); } // Our ellipse drawstring backstage static last Drawstring mEllipsis = "..."; // Registered resize listener backstage OnTextResizeListener mTextResizeListener; // Emblem for matter and/oregon dimension modifications to unit a resize backstage boolean mNeedsResize = mendacious; // Matter measurement that is fit from codification. This acts arsenic a beginning component for resizing backstage interval mTextSize; // Impermanent high bounds connected the beginning matter measurement backstage interval mMaxTextSize = zero; // Less bounds for matter dimension backstage interval mMinTextSize = MIN_TEXT_SIZE; // Matter position formation spacing multiplier backstage interval mSpacingMult = 1.0f; // Matter position further formation spacing backstage interval mSpacingAdd = zero.0f; // Adhd ellipsis to matter that overflows astatine the smallest matter dimension backstage boolean mAddEllipsis = actual; // Default constructor override national AutoResizeTextView(Discourse discourse) { this(discourse, null); } // Default constructor once inflating from XML record national AutoResizeTextView(Discourse discourse, AttributeSet attrs) { this(discourse, attrs, zero); } // Default constructor override national AutoResizeTextView(Discourse discourse, AttributeSet attrs, int defStyle) { ace(discourse, attrs, defStyle); mTextSize = getTextSize(); } /** * Once matter adjustments, fit the unit resize emblem to actual and reset the matter dimension. */ @Override protected void onTextChanged(last CharSequence matter, last int commencement, last int earlier, last int last) { mNeedsResize = actual; // Since this position whitethorn beryllium reused, it is bully to reset the matter measurement resetTextSize(); } /** * If the matter position measurement modified, fit the unit resize emblem to actual */ @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { if (w != oldw || h != oldh) { mNeedsResize = actual; } } /** * Registry listener to have resize notifications * @param listener */ national void setOnResizeListener(OnTextResizeListener listener) { mTextResizeListener = listener; } /** * Override the fit matter dimension to replace our inner mention values */ @Override national void setTextSize(interval dimension) { ace.setTextSize(measurement); mTextSize = getTextSize(); } /** * Override the fit matter dimension to replace our inner mention values */ @Override national void setTextSize(int part, interval dimension) { ace.setTextSize(part, dimension); mTextSize = getTextSize(); } /** * Override the fit formation spacing to replace our inner mention values */ @Override national void setLineSpacing(interval adhd, interval mult) { ace.setLineSpacing(adhd, mult); mSpacingMult = mult; mSpacingAdd = adhd; } /** * Fit the high matter dimension bounds and invalidate the position * @param maxTextSize */ national void setMaxTextSize(interval maxTextSize) { mMaxTextSize = maxTextSize; requestLayout(); invalidate(); } /** * Instrument high matter measurement bounds * @instrument */ national interval getMaxTextSize() { instrument mMaxTextSize; } /** * Fit the less matter dimension bounds and invalidate the position * @param minTextSize */ national void setMinTextSize(interval minTextSize) { mMinTextSize = minTextSize; requestLayout(); invalidate(); } /** * Instrument less matter dimension bounds * @instrument */ national interval getMinTextSize() { instrument mMinTextSize; } /** * Fit emblem to adhd ellipsis to matter that overflows astatine the smallest matter dimension * @param addEllipsis */ national void setAddEllipsis(boolean addEllipsis) { mAddEllipsis = addEllipsis; } /** * Instrument emblem to adhd ellipsis to matter that overflows astatine the smallest matter measurement * @instrument */ national boolean getAddEllipsis() { instrument mAddEllipsis; } /** * Reset the matter to the first measurement */ national void resetTextSize() { if (mTextSize > zero) { ace.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize); mMaxTextSize = mTextSize; } } /** * Resize matter last measuring */ @Override protected void onLayout(boolean modified, int near, int apical, int correct, int bottommost) { if (modified || mNeedsResize) { int widthLimit = (correct - near) - getCompoundPaddingLeft() - getCompoundPaddingRight(); int heightLimit = (bottommost - apical) - getCompoundPaddingBottom() - getCompoundPaddingTop(); resizeText(widthLimit, heightLimit); } ace.onLayout(modified, near, apical, correct, bottommost); } /** * Resize the matter measurement with default width and tallness */ national void resizeText() { int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop(); int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight(); resizeText(widthLimit, heightLimit); } /** * Resize the matter measurement with specified width and tallness * @param width * @param tallness */ national void resizeText(int width, int tallness) { CharSequence matter = getText(); // Bash not resize if the position does not person dimensions oregon location is nary matter if (matter == null || matter.dimension() == zero || tallness <= zero || width <= zero || mTextSize == zero) { instrument; } if (getTransformationMethod() != null) { matter = getTransformationMethod().getTransformation(matter, this); } // Acquire the matter position's coat entity TextPaint textPaint = getPaint(); // Shop the actual matter measurement interval oldTextSize = textPaint.getTextSize(); // If location is a max matter dimension fit, usage the lesser of that and the default matter dimension interval targetTextSize = mMaxTextSize > zero ? Mathematics.min(mTextSize, mMaxTextSize) : mTextSize; // Acquire the required matter tallness int textHeight = getTextHeight(matter, textPaint, width, targetTextSize); // Till we both acceptable inside our matter position oregon we had reached our min matter measurement, incrementally attempt smaller sizes piece (textHeight > tallness && targetTextSize > mMinTextSize) { targetTextSize = Mathematics.max(targetTextSize - 2, mMinTextSize); textHeight = getTextHeight(matter, textPaint, width, targetTextSize); } // If we had reached our minimal matter measurement and inactive don't acceptable, append an ellipsis if (mAddEllipsis && targetTextSize == mMinTextSize && textHeight > tallness) { // Gully utilizing a static format // modified: usage a transcript of TextPaint for measuring TextPaint coat = fresh TextPaint(textPaint); // Gully utilizing a static format StaticLayout structure = fresh StaticLayout(matter, coat, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, mendacious); // Cheque that we person a slightest 1 formation of rendered matter if (structure.getLineCount() > zero) { // Since the formation astatine the circumstantial vertical assumption would beryllium chopped disconnected, // we essential trim ahead to the former formation int lastLine = format.getLineForVertical(tallness) - 1; // If the matter would not equal acceptable connected a azygous formation, broad it if (lastLine < zero) { setText(""); } // Other, trim to the former formation and adhd an ellipsis other { int commencement = structure.getLineStart(lastLine); int extremity = format.getLineEnd(lastLine); interval lineWidth = format.getLineWidth(lastLine); interval ellipseWidth = textPaint.measureText(mEllipsis); // Trim characters disconnected till we person adequate area to gully the ellipsis piece (width < lineWidth + ellipseWidth) { lineWidth = textPaint.measureText(matter.subSequence(commencement, --extremity + 1).toString()); } setText(matter.subSequence(zero, extremity) + mEllipsis); } } } // Any gadgets attempt to car set formation spacing, truthful unit default formation spacing // and invalidate the structure arsenic a broadside consequence setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize); setLineSpacing(mSpacingAdd, mSpacingMult); // Notify the listener if registered if (mTextResizeListener != null) { mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize); } // Reset unit resize emblem mNeedsResize = mendacious; } // Fit the matter measurement of the matter coat entity and usage a static format to render matter disconnected surface earlier measuring backstage int getTextHeight(CharSequence origin, TextPaint coat, int width, interval textSize) { // modified: brand a transcript of the first TextPaint entity for measuring // (seemingly the entity will get modified piece measuring, seat besides the // docs for TextView.getPaint() (which states to entree it publication-lone) TextPaint paintCopy = fresh TextPaint(coat); // Replace the matter coat entity paintCopy.setTextSize(textSize); // Measurement utilizing a static structure StaticLayout format = fresh StaticLayout(origin, paintCopy, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, actual); instrument structure.getHeight(); } }

Informing. Location is an crucial mounted bug affecting Android three.1 - four.04 inflicting each AutoResizingTextView widgets not to activity. Delight publication: https://stackoverflow.com/a/21851157/2075875