/**
* Computes the maximum font size which makes the TextView's (possibly multi-line) text fit in the
* bounding box defined by the viewWidth and viewHeight parameters, always within the range
* ({@link #MIN_TEXT_SIZE}, {@link #MAX_TEXT_SIZE}) but taking into account any predetermined font
* size constraints that come from the font size coordinator (if present).
*
* @param viewWidth the width of the View into which the text will be drawn (including padding)
* @param viewHeight the height of the View into which the text will be drawn (including padding)
* @param force whether or not to force a recalculation of font size (this could otherwise be
* avoided
*/
private void fitText(int viewWidth, int viewHeight, boolean force) {
// Avoid unnecessary (re)fitting: 0 or negative view dimensions
if (viewWidth <= 0 || viewHeight <= 0) return;
// Avoid unnecessary (re)fitting: text is empty
if (text == null || text.isEmpty()) return;
// Compute the target text width/height as the provided container width minus relevant padding
int targetWidth = viewWidth - this.getPaddingLeft() - this.getPaddingRight();
int targetHeight = viewHeight - this.getPaddingBottom() - this.getPaddingTop();
// Avoid unnecessary (re)fitting: no forcing and target dimensions are the same as last time
if (!force && targetWidth == lastTargetWidth && targetHeight == lastTargetHeight) return;
// At this point we know a new size computation will take place...
// Log.d("TFV", "fitText: IS REFITTING, text: " + this.getText() + ", hash: " + hashCode() + "
// w=" + viewWidth + ", h=" + viewHeight + ", forced: " + force);
// Initialise lo & hi bounds:
float lo = MIN_TEXT_SIZE;
float hi = (coordinator == null) ? MAX_TEXT_SIZE : coordinator.getCoordinatedTextSize();
// See if we can use the "hi" instead of iterating (if "hi" fits then iterating will only get us
// back to a value marginally smaller than "hi"):
float textSize = hi;
// Only iterate if "hi" was too big:
if (!textFits(textSize, targetWidth, targetHeight)) {
// Fitting loop (binary search):
while ((hi - lo) > THRESHOLD) {
textSize = (hi + lo) / 2;
// See if our text fits
if (textFits(textSize, targetWidth, targetHeight))
lo = textSize; // was too small, so increase lo
else hi = textSize; // was too big, so reduce hi
}
// We set lo as the new textSize, so that we undershoot rather than overshoot:
textSize = lo;
}
// Log.d("TFV", "final textSize for slot " + coordinatorSlot + ": " + textSize);
// Remember target dimensions:
lastTargetWidth = targetWidth;
lastTargetHeight = targetHeight;
// Set new textSize:
this.setTextSizePx(
textSize,
coordinator
== null); // if there is a coordinate the new size is not applied immediately but at a
// later time determined by the coordinator
// Inform coordinator if there is one:
if (coordinator != null) coordinator.updated(this);
}
/**
* @param context
* @param coordinator
* @param coordinatorSlot
*/
public TextFitView(Context context, TextSizeCoordinator coordinator, int coordinatorSlot) {
super(context);
this.coordinator = coordinator;
// Set or claim coordinator slot:
this.coordinatorSlot =
coordinator != null
? (coordinatorSlot >= 0 ? coordinatorSlot : coordinator.claimSlot(this))
: UNASSIGNED_SLOT;
// Initialise paint:
paint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
paint.setAntiAlias(true); // text looks pixellated otherwise
paint.setColor(DEFAULT_TEXT_COLOR);
paint.setTextSize(textSizePx);
}